2-ways and 3-ways

If the "3" is the bass then 2 way is superior. Why? Bass does not load in a room in the same physical location as the highs and mids. Also, as mentioned, the XO is more complex and fixed, whereas powered subs have separate control for volume, XO point and phase/polarity.

The problem with most 2 ways is their designers try to get too much bass from them

here's a shocker..it would all come down to what specific speaker you are talking about. its still about balance regardless of the design, when it comes to longterm satisfaction.

Phasecorrect: Just from a simplistic less is more standpoint...

That is simplistic alright, for if that were the case we would be listening to one piece boomboxes rather than multicomponent systems. :)

Actually, an argument could also be made in the exact opposite direction as well. Advances in materials and electronics have also led to full-range drivers becoming much better. In addition, a full-range driver speaker has NO crossover in the "presence" region, which IMO is always a better solution. If you need deep bass/sparkly highs, roll in a subwoofer or two on the bottom and a supertweeter at the top.

If the "3" is the bass then 2 way is superior. Why? Bass does not load in a room in the same physical location as the highs and mids.

Well, I agree, even though 2-way usually *isn't* superior!
BTW, you can get the lower mids/bass channel to mate with the rest in the same position -- at the expense of a few frequencies, however (you have to sacrifice something -- otherwise it won't work at all).