Time to upgrade the old Dual turntable, looking for opinions.

I bought my Dual CS-522 turntable new back in 1980 and it's well past time to think about upgrading. This model was more or less at the bottom of Dual's range back then, but it fit the budget. One of its interesting quirks is that the platter was never totally flat (these were stamped platters, not cast ones) and even though I replaced it about 12 years ago years, it's improved but not perfect. Our vinyl collection, comprising well over 400 records, has remained largely idle for many years but it's still with us and really needs to be heard. So, I'm curious to get some opinions about what modern (or for that matter, vintage) TT's might be a significant upgrade. Hoping not to exceed $1500 for this, but can stretch a little in the right circumstances. (Finding a significant upgrade for my ClearAudio Micro Basic phono preamp is a separate project, but we'll get to that).
You should be able to get a Linn turntable with tonearm and cartridge used for less than what you mention. Even a Linn Basik would be a significant upgrade from your Dual.

You can't go wrong with a Rega RP3 or RP6.

There are lots of options in the $1500 range. And it's a good place to be, dollar wise, that is where you jump over beginner tables and get to some real entry level high end tables! 

Shopping used, you've got many options, I paid $1100 for a VPI Scout, and put a Sumiko cartridge on it, and I am very pleased! I have no plans to upgrade any time soon. Perhaps I'll upgrade to a better cartridge one day, but the 'table is great. My son in law has a Music Hall Ikura 'table that sells new for $1200, and he loves it. Then there is the Clearaudio Concept that comes complete, about $2 grand new, but used ones aren't hard to find. I've always liked the Marantz TT-15, a complete outfit that's actually made by Clearaudio with a Clearaudio cartridge on it for $1500 and change new. If you like low mass, the Rega Planier 3 is about $1300, and Sota tables can be had used in this price range too. The first high end 'table I ever heard was a Sota, and it changed my entire outlook on vinyl! so many companies jumping in at this price point with some real high class tables! 

Any one one of these could make you happy, a real step up from the basic stuff in the $500 range. Seems that most folks that start at the $500 range soon upgrade to the next step up, so save yourself the trouble and get something really nice, you will be awestruck at the difference from your old table to one of these new designs. And there are even more names that I haven't mentioned, Funk, Mitchell, Basis, etc.

some folks will preach on the restored greats from the past, and I've no problem with that. Thorens and Garrard, etc. if that's your preference nothing wrong with that. And the Linn tables are also excellent, and have an endless upgrade path! Sorry I couldn't narrow it down more. But I can testify that my Scout is awesome and I have no intention of upgrading any time soon. Happy shopping!

So, I’m curious to get some opinions about what modern (or for that matter, vintage) TT’s might be a significant upgrade. Hoping not to exceed $1500 for this, but can stretch a little in the right circumstances
Vintage is fine if your technically inclined!
And while many were built to great quality standards, most of these TT’s are now pushing 40 years old. If you go this route, expect to have to open it up and do some extensive repair or at the very least, intensive cleaning. No matter what the seller says!

Now if you don’t want the fuss that comes with vintage, go new. $1500 and bit higher can buy a lot of great sounding TT’s...

The GEM Dandy Polytable yogiboy recommended is a good one.
So is the VPI Scout Jr.
And finally if you want a vintage look but in a brand new unit built to the same extremely quality standards, then look at the new Technics SL1200GR. It’s 2 grand but will last a lifetime.

So here you have three radically different TT’s in design and drive implementation.. Two are built in the USA and the third in Japan so you can be assured quality.
Remember that a great TT is as much a precision machine as it is an electronic component.
I’ll second those brands/models identified in Alpha_gt’s post - and I own a Rega!

Back in 1985 when I bought my Rega Planar II - it was ahead of it’s time, great value and from a performance perspective, it challenged some of the "big names" in turntables.

Since then, I’ve upgraded almost all the parts on my Planar II to the point where the only thing that is "stock Rega" is the cover and the ON/OFF switch.

Even allowing for the large number of aftermarket upgrades that are currently available - If I had to choose today, I’m sorry to say I would not select a Rega.

Don’t get me wrong - I still think Rega offers good products, but they are now being seriously challenged - just as they challenged the "big names" - 35 years ago.

Will any other company match what Rega has achieved? - probably not.

But they also can’t afford to - "rest on one’s laurels"

Sorry Rega fans :-(
Thanks for the responses. I've certainly looked at the various models of Rega, Music Hall, VPI and Clearaudio among others, but as yet haven't done any active auditioning. At the moment I'm tending toward the used market for this, preferably local, though there is certainly an advantage to buying new, especially with respect to warranty service and possibly (though this isn't a central consideration) resale value if I decide to upgrade even further someday.
I use a Linn Basik/Akito (replaced the cable with a nice Mogami Jelco) rig and it’s so good I’m only considering replacing it because I don’t want to be there when it dies. I’ve concluded the following: Regas don’t allow for VTA adjustment, I understand why, but I refuse to use anything requiring shims. The lack of a dust cover also eliminates some models for me, as having to cough up the extra 350 bucks or so for a cover seems lame. I’m mildly interested in the new Pro-ject "The Classic" simply for its looks and perhaps design (more reviews will help me decide I suppose, although it has had some good press) as otherwise bouncy suspended tables can bounce…plus it’s around a grand with cartridge and all so there’s that.
Cooper52 - one last thought....

Turntables like the Rega - where the belt goes round the sub-platter, require the "Rega Nudge" to get them up to speed in order to minimize  wear on the belt/motor. But only if the platter is heavy like the Rega glass platters

Turntables that have a belt which goes around the outside of the platter get up to speed that much quicker and does not require the nudge regardless of platter weight. It's much less stress on the belt and motor but their belts tend to be a little more expensive.

Is it a BIG deal? - not really and certainly not a deal breaker - just something to consider.

However, if you have those high quality  45 rpm album sets that are out there - having to remove the platter to change speed may be a deal breaker. I have a couple and they do not get played that often.

Does anyone know of a conversion kit for this?

As always - Swings and roundabouts :-)
I have to remove the platter to put my Linn into 45 mode…I know I'll never get that 30 seconds back...*sigh*…and I'm often slightly drunk as I'm forcing dinner guests to listen to a single I played on in 1981…always worth it by the way…great single (released only in Japan).
REGA P3 with a Dynavector 10X5, a 2.5mv high output MC cartridge is ..pure audio excitement!!!!