"Moving up" the Thiel line as I have - 2.2's, 2.3's, 3.5's, and now 3.6's - does not necessarily infer that each was an improvement over the former inasmuch it does infer that each is rather different from the former, if not by definition "better".
The most immediately remarkable impressions were experienced from the 2.2's to the 3.5's - each had what the previous model had with a dash of mo' better everything tossed in.
The difference between the 3.5's and 3.6's is, with the 3.6's, a more pronounced, perhaps forward midrange that, to my ears, seems to soften the notably crisp highs of Thiel in general. This is not to say that the highs are suffered by any means, nor is the low frequency
response. The few low-end hertzes I was willing to sacrifice with the 3.6's mattered not a whit; the bass is palpable, tangible, there's an appreciable sense of timbre and naturalness. I can't even imagine a need for a sub. No, sir.
Me no likey subs.
Thus far I've found that the 3.6's show their finest at a volume level a little higher than I normally prefer. And it's there that everything pours forth - the music is felt, defined, passing "the other room" test, causing me to re-enter the living room and think, "what a genius I am to have found these speakers."
Many contributors to this thread have been fortunate enough to purchase these speakers used at considerable savings. Considerable savings over what a comparatively new purchase of another brand would incur. That alone has made Thiel my reference point for considering any other brand. Extraordinarily difficult to beat.
For now, the 3.6's won't move. They're too damn heavy for one, and secondly they're just too damn good. Did I mention they're heavy?
They're heavy. Swapping cables is something of a chore requiring tipping them onto their sides onto a carpet to get at the connects on the bottom. Oof. Ouch.
Up the line? Only the future knows...