Given the advances in tire technology I think all transaxle options, even quaife & others would struggle with reliability. Ive got customers that destroy the likes of G-Force & Jerico thru not being sensitive to the driveline and there have been posts on this site with complaints of ZFQ's expiring behind 400cu in plus strokers. The ZFQ was originally intended to be a 289 replacement. Part of the breakage issue is using U-Joint half shafts vs upgrading to stronger CV joints. Its not really a case of stronger material, but more of the rotating forces that build up in a U-Joint with angle changes etc. Used to be a thread on here with Comments from a guy who posted under the name of WANNI who knew his stuff and had contacts with high $$ tranaxle designs. He spoke of instances where the rear half shafts would twist a large number of degrees, with that fact in mind you should be able understand why a half shaft with U-Joints have a short lifespan.