As one of those older (well not that old), first-time RV-12 builders, I agree with everything Jetguy said. Keep in mind also that as an LSA, the RV-12
was a completely new design challenge for Vans - forward seating, different engine, removable wings, stabilator, very light airframe, etc. They did an outstanding job IMO, not only with the design but also with the sophistication and completeness of the kit and the quality of the plans.
As I see it, the RV-14, while also a new design, borrows far more from the other RV's than the -12 did. Therefore I would have no qualms at all about Vans getting it right. There will be minor glitches along the way, but certainly nothing to be concerned about. Vans will do a thorough job of both design and testing. Furthermore, if they package the kit like the -12 with standard avionics, engine, FWF and prefabricated plug-and-play wiring, they will have taken all the hard work out of building and have another winner in their lineup.
Although the one size fits all approach will not suit everybody, I'm willing to bet that most will opt for the Van's package when they see how much time and head-scratching it will save. Also, a standardised, well thought-out kit should also result in a fleet of safer aircraft, and safety is something that Van takes very seriously.