New mains to complement Usher 5.1 setup?


I have an Usher 5.1 setup with S-520 mains and surrounds, S-525 center, and SW-210 sub, currently driven by a Cambridge Audio CXR120 AVR. We will move in a few months to a house with a deeper AV area and I am thinking of expanding to 7.1. The easiest and surest move is to just buy a third pair of S-520s. But, I am open to upgrading the mains to floor standing speakers that will both play nicely with the existing Usher speakers for surround/theater, and provide an upgrade when listening to music in stereo. My budget will be the $2K range, new or used. The speakers will likely continue to be driven by a mid-fi amp for the foreseeable future, so nothing too revealing of amp flaws. Thanks for guidance and suggestions.
bgmanne
I’m a big Usher fan and think it’d be a great idea to stick with that brand if you like the sound. If you can stretch your budget a bit there’s a nice pair of Mini Dancer 2s available here now that you can probably get for around $3k give or take. At 90dB sensitivity they should work with your AVR for now, but they’ll surely reward you greatly as you improve the equipment you feed them with so you can grow into them — LOTS to look forward to there. The MD2s will bring you to entirely new level of musical enjoyment.  Oh yeah, and they’re gorgeous. Best of luck.
Thanks for this.  $3K is a stretch at the moment.  There is also some concern for placement, as this is an AV setup in a living room/den, not a dedicated room, and I read that the MD2 is somewhat fickle about location, and requires lots of room to breath.  I may need something more forgiving about location (and less expensive.)
These are excellent all-around speakers with a similar sonic signature to Usher...

https://tmraudio.com/speakers/bookshelf-speakers-monitors/joseph-audio-rm7xl-bookshelf-speakers-black-pair/

If you prefer new the LSA-10 Signatures are available here from the manufacturer for $1200/pr and would also be excellent.  Just a couple more ideas...

Perhaps consider the N6311 or N6361. They are based off the CP-6 series and represent great values.
Usher N-6361 looks like an intriguing option.  Any thoughts on GoldenEar Triton 3 / 3+ ?
Uh, forgot to mention the obvious upgrade to the Usher SD-500 that goes for about $2k/pr new.  Duh.  It’s pretty impressive to be able to get their flagship diamond tweeter at this price level, but then it’s Usher so not really surprised. 
Thanks for mentioning the SD-500.  I have had floor standing speakers in mind, but I should be open to monitors at my price point.  Interestingly, I emailed pretty much the same inquiry directly to Usher's US distributor at the time I posted this yesterday, but have not heard back from them....

I’ve decided to go with a pair of mini dancer 1s. I purchased now with a holiday sale discount, but retailer will hold until I’m ready to receive them at the new house. I’ll eventually return with some comments after I’ve lived with them for a while.

Congrats on some AWESOME new speakers!  Now the bad news — I absolutely FORBID you to drive these beauties with an AVR.  It’d be an insult to them and you won’t hear half of what you paid for.  My advice — start looking for  a new AVR that has preamp outs and a good stereo integrated amp.  Anyway, congrats again on your incredible new speaks!

Now I’m really missing my beloved Plinius 8150i, with the ultimate Galbo mod….