Should I keep the Turntable or sell it?

I’ve been back and forth on this decision for about a month, and the more I learn, the harder this decision gets.

Backstory: I won the brand new Cambridge Audio Alva TT turntable in an online contest in mid-May, and while it sounds great, I decided to list it for sale a couple weeks ago. I’ve always wanted to try out a Rega P6 or P3 with a really nice cart, because I feel like I’m not getting enough out of my Pro-Ject Debut Carbon. Prior to winning the Alva TT, I switched the Red Ortofon out for the Blue, and there was a great improvement in sound quality. But after comparing the Pro-Ject to the Alva TT and hearing what a $1700 turntable can sound like, I definitely am interested in exploring more high fidelity turntables. The issue is that I feel like I prefer the sound of tubes over solid state, and the Alva TT uses an integrated Alva Duo phono preamp for the RCA out, and their own DAC for the Bluetooth out if I want to go that route. I don’t have a ton of experience with tubes, and maybe it’s just the “cool factor” I actually like and I’m just having a placebo effect.

So I decided to list it for sale to try and get a Rega, because I heard so many great things about them. But over the last week or so, I’ve learned more about the Alva TT and how it uses Rega’s famous tonearm. I looked up the cart and it is listed at $500 separately, which is probably why it sounds better than the Pro-Ject w/ Ortofon Blue. I’ve also read on these boards about direct drive being better than belt, which the Alva has as well. It also has the added bonus of Bluetooth that go directly to my KEF LS50 Wireless, but I would most likely just use interconnects.

So I would love to get some advice from you all. I’ve gone back and forth about keeping the Alva or selling it, along with my Pro-Ject Debut Carbon, and buying/trading for something like a Rega P3 or P6. If you had my first world problem, what would you do?
noromance2  it is much easier to work at the cartridge end then at the bearing end. Establishing the proper angle might just require a little paper or a matchbook cover. 
Wow, just how fast can a simple question deteriorate? Both DD and Belt drive have their good and mediocre sides. If you want DD go get the one you can afford if your a disc jock if not put your money where your ears tell you to put it. Belt drives can and do outperform DD so don't play the hype. I went from DD to belt and have no regrets but do wonder when the belt will break, stretch etc. Hasn't happened yet.
Don't buy into the hype, buy what your own ears tell you.
@mijostyn Shims at the cartridge end will only work in one direction and paper/card will compromise the integrity of the cartridge/headshell coupling.
Well; I don't know how well the OP's question was addressed, but this has been the most entertaining, thread I've read on Audiogon in years, with all the back and forth debate and subtle character assassinations.
@boofer lol... yes, it was quite the train wreck at first, but many folks on here offered great ideas and information. I’ve decided to try and trade in my two units for either a Marantz TT-15S1 or a Rega P3 with Exact cart. The Music Hall 7.3 came in third place for my preferences. I feel like there has been a number of comparisons on the web with these two units, and it comes down to which audio dealer will make me the best trade offer for one of those tables.

In the end, I know I will be happy with either of those two tables. 

But of those two options, which one would you personally go with?