I haven't tried waxpolish soft, but I plan on getting some. I have used the Ultra, Paint, and Metallic polishes and the Glanz wax. I like each one alot. The WPS sounds like Metallic with a bit more bite, which sounds great to me. I like the Glanz wax alot also.
I also have AIO and SG and agree that they are good products. I find SG a bit difficult to work with. I have 2 black cars and find the SG just is a pain to take off. I have tried everyone's different method for removal and find that I would rather just use Glanz wax than go through all the issues with SG. Besides, Glanz lasts as long according to most reviews and is much easier to work with. Also, Metallic contains carnuba waxes that will last 4 to 6 weeks or so. That has been my experience
Of course, that being said, I have alot of waxes and polishes and always seem to be touching up a fender with Metallic and then throwing on a layer of S100, or just putting on a layer of EX because I can use it in the sun. .
However, when I need to get something done and done right, I always reach for the 1Z polishes.