$5000 or under speaker secommendations?


I'm thinking about getting a second, used pair of either bookshelf or full range/floorstanding speakers for my system (currently I have the Avalon Radiants and love them).

Not wanting to spend my child's college tuition on this second pair, I want the best money can get for a pair that would typically list around $3,500-5,000 new. I'm considering the Martin-Logan Aerons or Ascents, Opera Callas, Thiel CS 3.5, and Sonus Faber Electa models, but am wide open to other recommendations.

Anyone care to share their opinions, preferences, favorite picks?

Thanks!
output555
Von Schweikert's have several great speakers in this price range VR4 latest generation (used, new may have went up recently)
Martin Logan are very good, I use them exclusively in the HT system but they do need very musical gear to sound pleasant, otherwise they are VEEERY revealing ... beware here! ... however you can never forget their sound if you like it.
I would recommend B&W 703, 804, 805, or 803S speakers. I have 703s and couldn't be happier, until I get to upgrade to 803D or 802D speakers down the road at some point. Best advice is to go take a listen somewhere, it convinced me pretty quick... :)
I have been utterly astonished--and delighted to the point of giddiness--by the wonderful sound emanating from my recently purchased Intuitive Design Summit loudspeakers, around 3500 for the speakers and 1500 for the stands. I plan a review at some point but want them to break in some more. If possible, give them a listen. Small company, well worth checking out.