RE: What has to be the best trainer.....ever!!
I 'll agree with the Avistar -- one great-flying plane & it can be "tuned" down to basic trainer level. It also makes a pretty good hot rod with a little bit of "tuning-up".
Just for the record, I don't recommend any SPAD, although I have five of the little brutes myself. They just don't fly as well as a standard trainer, & cheapness & durability are poor trade-offs for the penalty of inhibiting a student's progress.