My experience has been very positive. The IMP line of plans are mostly, if not all, from Cluade Baskins. I have built 4 of these (Ki-100, Typhoon, Hellcat, and a wing for my 106 inch Me109). They all fly well, and I think they go togehter pretty good. In my experience, no plan kit has the parts fall togehter perfectly, but I have found the IMP plan builds to go very well....every bit as good as Ziroli. I cannot speak for the IMP wood kits, as I cut all of my own parts.
For anyone interested, I am currently building a 147 inch Spitfire Mk. IXB from 200 percent enlarged Claude Baskin plans obtained from IMP scale. You can go here to see the project:
http://www.rcscalebuilder.com/forum/...?TID=9766&PN=1
Jeff