Very very well, no issues. nope they reprogram your stock ecu, nope it all fits on the 09 bottom end. Kit uses there custom separate jugs and pistons. I have nothing bad to say about it at all. IMHO it is the BEST fix you can do to a 800cfi, only issue is cost spendy $$$$$ jugs are around 1000.00 each, you will have over 4k in the kit.
My friend has it on his sled, rides the piss out of it no issues at all, powers about equal to a turbo 800 at 6-7 pounds +/-