If you have a system based on HT3, and you find that it is a little 'bright, switching to 5A will give you more 'midrange details" at the expense of losing a little of 'sparkling' in the high. Getting the right 'detail' out of your system is really a delicate balancing act. Every component in your system counts, not just the speakers. Hence a system that's a little 'bright' may give a more 'sparkling' or excitement in the high frequency, but it may mask out the delicacy in the midrange. I used to run Nordost Valhalla IC from my preamp to my amp, when I switched to Gabriel Gold Revelation Mk II, I immediately hear more 'low-level detail', because the Gabriel is a 'warmer' IC than the Nordost, it makes the high less dominating and brings out the midrange a little bit more. And don't forget we're talking about small subtleties/delicacies here, a small tweak here and there (e.g. the right isolation) can get you to where you want to be.
I know a guy down here in Houston who used to owns a 5A, I certainly do not hear more 'low level details' in his system than mine. He has moved on and now owns an Egglestoneworks Andrea II - which is another good speakers worth consideration in the $20k price range.
For reference, stereophile has this definition of the term "detail"
low-level detail The subtlest elements of musical sound, which include the delicate details of instrumental sounds and the final tail of reverberation decay
I hate to keep coming back to the 5A's, but I not only get more warmth in the mid-range, they also pass along more details than the HT3's.