If used works for you - try to find some JMLabs/Focal 714s. Strong performance, easy to drive and good looks!
Check out the PSB Image T45 floorstander. List price is $800/pair, but if you shop around you can probably find a pair at your budget. The PSB Image series are exceptional at their price in several ways, including good sensitivity, low cabinet resonance, linear frequency response, and wide, uniform dispersion for excellent interaction with the room they're in.
Fortes..Easy to drive..Modest size cabinet( 3'high ) ..Work well with Vintage Receivers and Intergrateds..( exc with Sansui Au series ) ...Play loud,Big bass,easy to set up ..A touch on the warm/lush side ( at least for me with Sansui )..Work very well with solid core cables ( Anti cables ) ...For $600 ish they are pretty hard to beat..
Klipsch Forte's. $400 to $600 in used market. From my experience, most Klipsch owners of these classic or heritage speakers take good care of them. Take a good look at the passive radiators on the rear, if any damage to the speakers this is where it will occur. Great sounding with tubes and most vintage receivers or int. amps. Also like a lot of power even though not necessary.
05-23-09: WilllandOr at a list price of $658/pair, consider the in-production Klipsch RF-52 column speakers, with the more modern touches of a narrow baffle with dual metallized woofers and a horn-loaded titanium dome tweeter instead of compression driver. They have the Klipsch trademarks of very high sensitivity (96 dB), clarity beyond their price range, ability to play loud cleanly, and bass extension (to the mid-30s). The Perfect Vision (a TAS spinoff) gives a very favorable review here.
"Do arro's have good bass? Please tell all."
Not the dynamics and meat on the bones of some of the best, but I'd say the bass on Arros properly driven is extraordinarily good for a speak in its price range and especially with such a small footprint. It is in the same league as many speaks costing 2-4 times as much I would say. Surely better than Maggie mmg, which I also like very much in its price range. Maybe not as extended as Klipsch Forte.
Well, I can't speak for the Wharfedale 9.6, but i've had a pair of Wharfedale Diamond 7.3s for ten years. They are good at doing the intimate thing--almost as fast and transparent as an electrostatic, but even though the 7.3 is a mass-loaded floor-standing version, it's pretty thin on the bass, so I couldn't get excited about it. That doesn't say anything regarding what they've done with subsequent generations (the 9.4 is closest to what the 7.3 was). The 9.6 is a 3-way with twin woofers and twin ports, so it probably has significantly more bass than my 7.3's.
I still think you should check into the Canadians--PSB, Paradigm, and Energy. They are all based on research done at Canada's National Research Foundation, and all are reasonably sensitive, have wide, even dispersion, a transparent natural-sounding midrange, and good, extended, clean bass for a given enclosure size.
There is a pair of Sound Dynamics 300Ti on the GON right now for $225.00. I don't know the seller but I know those speakers. I first heard about them in The Absolute Sound mag when the editor (HP) flipped over them. Then I found a used pair for a friend and got to hear them in his system and couldn't believe how good they were for what he paid for them ($350.00)! Do a google search on them and you will find nothing but praise. Good Luck
Big +1 on the Sound Dynamics 300ti! I don't know how many pairs of those I recommended to friends when Audio Advisor was closing out the last production run at $500/pair. Every single buyer (and there had to be about a dozen) I know who bought was absolutely ecstatic about what those speakers brought to the party.
That also says something about how amp-friendly they are. Most of these people plugged them into mass market receivers. For one guy, however, it sparked off a complete system upgrade and overhaul, with new (closeout) Counterpoint electronics, upgraded CD player, new cartridge, etc. I heard the 300ti's at his house and a couple pairs at another house, and they simply sound right with no obvious weaknesses: Smooth even in-room power response, wide, uniform dispersion, frequency extension at both ends with smooth treble and clean tight bass.
Upscale Audio is closing out the Triangle Heliade @ $700/pr new. This is a little over your stated limit, but the speaker was competitive at its list price of $1400/pr, so it's worth at least thinking about. It's a good looking, good sounding, easy to drive tower speaker with a smallish footprint. The only real downside in that response below app 40hz is MIA.
Athenas would share the API "house sound" with the SD300ti's, which are also an API speaker. The Athenas are probably a little faster and cleaner.
Compared to the Arros, the 300ti would sound fuller and more extended. The Arro would be faster, more transparent, but not as extended or full-sounding in the bottom.
If you want floorstanders that don't need help from a subwoofer and your upper budget is $600, you probably need to buy used, grey market, or closeout. These PSB Image T65's are evidently very lightly used with some original packing, and are nearly half off from a $1200/pair list.
You want something that will do "mostly rock, some classical and jazz" on their own? These will. They don't have the limitations of the Maggie MMGs or minimonitors in sensitivity, bass extension, or dynamic range. The PSB's are also some of the most linear speakers at any price from about 150 Hz up. Bass reaches effortlessly to the low 30's. They also do nuance, detail, and microdynamics well. Midrange and voices are transparent, "in the room" and dynamic, neither recessed or pushed forward.
The remaining consideration is whether your room is big enough to take them. They're only 8.5" w by 38" h, but they're 20 inches deep, which translates into more real bass power and extension while maintaining a petite baffle width for maximum dispersion and soundstaging.
Disclaimer: I have NO affiliation with the vendor of the linked listing. I am familiar with the T65s and helped a friend get some for his complete system makeover. He's very happy with them. The PSB T65 is a great value at retail, but at half off, it really gets you some decent champagne for beer money.