The bolts that come with some brakes are too short for post mount IMO. If you go from an IS adaptor to a post mount fork I suggest changing the bolts for the longest ones that will fit. Screw in a bolt without the brake caliper to find out how much thread there is in the fork, and then find or cut a bolt that sticks out of the caliper a millimetre or two less than that.

As for the choice of fork, all the recent forks I've tried have worked very well which makes choice harder than ever.

Sorry, bit late but revs get my vote.  I have air u-turns and while the coils are smoother the airs are more adjustable and lighter.  Plus with the u-turn thing you can adjust them to get the travel/angles you want.

Oh and they are seem to be pretty resilliant, mine have ploughed through two years worth of winter mud and only now am I considering a service.