I have been around the VW aircraft engine world for over 20 years. My first was an 1835, which was adequate. 135mph in my KR2. Cracked engine case forced a change so I built it up to a 1915 and saw smoother performance, but not much else. My next KR2 had a GPASC 2180 which over heated the oil badly until I put on some oil cooling mods from Revmaster. I have spent a lot of time talking with Revmaster and looked at their engines very closely. If I were to use a VW, there would be no doubt that it would be a Revmaster because I don't think either of the other two are even close to the quality put out by Joe Horvath at Revmaster.
I now have a 2700 Corvair built by Roy Szaravinski at RoyGarage.com and it is a great engine. If I could afford it, I would seriously be considering the UL Power engines, but for an economical engine, if your plane can take the weight, a Lycoming 320 would be great for slightly less weight, get a re-built Cont 0200 if you can find one. I understand that the 320 is the easiest to find because there are so many of them. See N64KR at <http://krbuilder.org/> http://KRBuilder.org - Then click on the pics 2015 KR Gathering - McMinnville, OR. September 3 - 6 -- See U There. Peoples Choice at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best KR at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Interior at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Paint at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Firwwall Forward at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Interior and Panel at 2008 - KR Gathering in Mt. Vernon, Il - MVN Daniel R. Heath - Lexington, SC