the SV-51 is a risky bet, since we don't know anything about it.
The VF-0 booster and the YF-19 are pretty safe bets, imo.
According to Graham, the shin type VF-0 will have the new POM arms which should make it a much more durable toy. and from most accounts, the YF-19 has been pretty good. No huge problems, though some members here have had really bad luck with theirs.