I really like my Blue Pig X and it feels nicer than the 2 PAs I had (more stable in the front, slacker, more give in the back, headtube/seattube size, mud clearance etc). Being able to fit a tapered fork, 30.9 dropper and route the cable/hose to do so is handy.
If you can grab a 2nd hand BPX then do, the newer non-X frames are £315 here: http://www.justmountainbikes.co.uk/delivery_pricing and at CRC.
Be aware that the mk1 frames had slimmer tubes for the head and seat tube.
It’s hard to describe but the BPX feels stiffer than the PAs, 456 and Latitude I’ve tried but yet with more compliance in the rear end in a good way. I think it’s something to do with the mumbo jumbo that’s been done to the stays as well as the odd butting in the front triangle.