Ptex doesn't actually solve the issue. its just like the magic unusable auto uv. its good for certain things not all things.
Ptex is fine for getting the colors onto your model and sticking them there*. But again if you want to use photoshop they are useless. It depends on what you do. Its not a silver bullet, it works for a lot of things but fails for a lot of things. It really depends on what you do.
BTW. you can do the same thing as PTEX already all you need to do is have humongous polycounts and use per vertex coloring. All ptex does is allows you to map these from a hires mesh to a low res one WITHOUT needing to actually have the geo in place. Plus doings all the boring job of filtering.
But yeah PTEX is great just not great for everything. I still need to do UV's for a lot of things even WITH ptex**, just not for all the damn things i would need to ever texture. So yes its better for maybe 75% of the MOVIE tasks out there.
IF on the other hand your doing interactive models for gaming then your still stuck with texture maps for the foreseeable future. Because the extra complexity can not be spared, nobody wants a 0.1 fps game because its easier on your end.
- and avoiding a s*!tload of problems with uv filtering (at the cost of some serious computational complexity), but only un subdivison models.
** lots of thisga are easy to do if you have a uv map. because its simple. It depends really on if you want complexity up front or complexity later.