2 way, which are the best designs?

Here Kenjit, maybe this will help to start:

https://www.cnet.com/news/the-art-of-speaker-design-explained-by-a-master/

To seek enlightenment, you should first stop trolling "useless" threads.

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!

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. 

Fritz speakers are top notch, very high quality. Could very well be my next pair of speakers when the time comes. Please be advised to ignore Kenjit on matters regarding quality of speakers where he only offers up an ax to grind.

Reasons why:

1) Best of show sound when I heave heard them and that includes soundstage and imaging
2) Unique crossover design that provides an easy load to drive.....even a few watts of tube power can do very well with excellent bass extension for the size and few if any other high quality speakers this size can do this particular trick
3) Only high quality third party parts used and yes also high quality cabinet.
4) These can deliver a lot of top notch sound especially for smaller monitor speakers off most any amp.
5) Top notch sound + top notch quality + relatively small package for all that = top notch value.