Alta are musical and rounded, but very resolving with no etching. It enabled me to better hear every difference I made in my system after. Many have compared them to perform at the range of $25K speakers, and I would vouch for that. At the NY audio show last year, they were the best of show to me outside of the $25K Martin Logan flagships.
I would say that if your system sounds bright or neutral, these speakers will do well for you, but if you already have a warm sound (The A-S2100 leans that way), you may need to use silver cables to get the right balance (not necessarily a bad thing!).
Happy to answer any any questions you may have on them. I don’t think I’ll ever upgrade.