For nearfield listening: which of these towers?

I initially replaced the Arro with the Quad 21L which I also quite like, and still use.

Yes, I've had both in 13x15 room and Silverline bass IS all of above,IMO a better speaker than Arro . Never heard the Bachs.
Preludes do better single not bi-wired . PRAT as the Brits say, is outstanding, they have no faults I've ever heard.
Easy to drive as well, mine do well with 8 tube watts from an Eastern Electric Mini-max 6bm8 integrated.

What about a monitor instead of tower? Something like the Ascend Acoustics Sierra-1? Still, would be nearfield listening at my desk, fairly close to wall, low to medium volumes, and still no sub. Would a monitor be better for this type of listening?

I currently use the Vienna Haydn Grand for desk top - sounds great...

Thats easy, a pair of Totem Dreamcatchers, one of the best speakers ever .
Followed closely by Silverline Minuets.