I was confused by this initially, but after an extensive demo of the v10 at a store I decided I was pleased with the blu ray performance so I went for it and I am still pleased with the decision.
I think, though I'm not sure, and it would be great if someone from what hifi confirmed this (possibly again since I may have read it on this forum) that the picture on both is pretty much the same, but that the criticism is made because the v10 is about £300 more expensive and so on a pound for pound basis, doesn't represent the best value for money. ie it is competing with products in a different price bracket and it is for this reason that the blu ray performance may be slightly disappointing, not because it doesn't perform as well as the g10.
As I say, someone at what hifi would have to confirm (or deny) this though.
In my opinion the v10 is very good, but then again I would say that. The best thing you can do is go to look at them both and see what you think - go by what you think, not by what you have read (though a thumbs up from this mag is always a good sign!)