I would have to say that out of all the Macross Plus toys Yamato has done, the VF-11B is by far the best. The only flaw I can come up with is how difficult it is to get the shoulders to sit in fighter mode. The hip joint really wasn't a big deal for me, because I was able to do some reconstructive hip surgery and now it's stronger than before. I even contemplated breaking the other one just to make it stronger, but I didn't have the balls to do it. As faw as the new releases, I can live with a 1/60 but I'm not a big fan of the 1/60 VF-1's. Now if they were to come out with perfect transformation 1/60's I would be a happy camper.
As for the YF & VF-19, It's a little hard keeping them standing in battroid and gerwalk modes, and they don't really look as impressive in fighter mode as the do in the cartoon/game. Difficult to transform and very unbalanced.
The YF-21 is just plain old ugly in my opinion, except for maybe the fighter mode. The chicken legs really turned me off to that one, so I didn't even bother getting it.