2 way, which are the best designs?

You can say whatever you want.

I am only saying it about the Fritz speakers.

See the difference?

Fritz  speakers are NOT efficient.  They present an easy load to drive by design, no tricks.  You are confusing two different things. 

Check out the Spatial Audio M Sapphire series. I don’t know that they’re the "best" (best is subjective). However, their predecessors, the M4 Triode Masters, were one of the best values I’ve encountered, easily competing with speakers of 2X their price.

I’m listening to a pair of $600 Vanatoo Transparent One Encore active speakers in our 12x12’ sunroom with vaulted ceiling and Gotta say in there these sound about as good as most any stand mount monitor speaker I have heard at any price. That includes some very popular brands in these parts. I can’t hear where they really lack anywhere except in that they do not do the bottom octave much but even with well recorded organ music, I don’t feel you are missing much at least in that room which has seen many speakers come and go in it. Very impressive!

I have Sierra2ex and I really like them. I’ve heard people say they are “too neutral” but I pair them with a tube preamp and a couple of SS monoblocks and it sounds pretty rad.

I'll say another good word about Ascend Acoustics Sierra-2.  I don't have the EX version, but they're very, very good; the highs are wonderful.
But I'll also say (repeating) that the WaveTouch Audio Antero is the best-sounding stand-mount speaker I've ever heard.