I've got one as well
I haven't noticed lag issues at all...
After installling the kit, boost has considerably increased. In cold weather my 33 boosts around 11-12psi- and thats with the standard solenoid (no aftermarket boost controller)- dont ask me how... its nice but!
overall, response has definitely improved.
the kit was quite easy to install. I didnt use all of the brackets, nuts and other bits that came with the kit, i bolted the cooler straight up from its top bracket onto the front centre chassis bracket (that mounts horn, bonnet latch etc.), and from memory- used tech screws to mount the bottom left cooler bracket to part of the lower left vehicle chassis. It sits nice & tight, wont move without some decent force
quick snap:
sorry bout bad quality - camera phone!