It's very good in many respects, with many features I appreciate.  But it's also limited in other respects.  People using the big three I know of, Maya, Max, and C4D, have been able to do things you just can't do with Poser's cloth.  Even Blender, which I use, has significant weaknesses compared to Poser, but has many more capabilities Poser simply doesn't have.

For example, most systems allow you to weight map your cloth, so you can control how dynamic it is. Poser can do that for the much more inaccurate soft body simulations (which they've said explicitly is too inaccurate to use on clothing, as has been my experience), but not on cloth.  Just being able to smoothly transition from constrained to dynamic would be a great advantage. 

That doesn't even get into raw quality issues.  I've tried many things that should have worked in theory, but even taking the steps per frame to 40 didn't make Poser's calculations work right.  Conversely, I've been able to do very fine work in Blender.

IIRC, AlfaSeed use Maya, and it's pretty obvious they build  their stuff with dynamics.  They don't work with Poser dynamics at all.  If Poser's tools could give them better results, I'm sure they'd use them.

I use displacement maps in Poser all of the time with no problems.  Which isn't unique; I learned from tutorials by people like Stonemason.  3Dream's displacement based hair products are doing quite well in the market.  What problems have you had with them?  I'd really like to know if there's a usage I need to account for.