I picked one up last week to try, used it for a few days but really not impressed.
It didn't seem to offer anything in the game except I liked the felt transition in/out of translation lift in heli's. Spent ages tweaking and trying others profiles but didn't find anything that I thought made it worth the HUGE downside.
Which is comfort, I have an expensive ergonomic chair which is amazing. Throwing a 2 inch thick pad on top it totally screws the comfort levels and being fairly narrow you feel almost perched on top, then of course you're sitting on top of a plastic seat now so sweating is also fun and it's not exactly warm here in the UK yet.
Anyway, it's waiting to be picked up by Amazon. To me not worth it at all.
Going to try a pair of transducers next attached either side of the chair see if that works for the same feeling but keeping the comfort of the chair.
Any questions ask away.