The Play journalist who wrote the Lair review for their magazine (he gave it a 9/10) makes his face known on neogaf, stating that they reviewed the same build as other journalists. This review copy had a poor framerate, and other bugs - but they were assured by Factor 5 that this would all be fixed for release - they thus reviewed it in this knowledge:
"We (Play) received the same review copy that I assume all the other mags did, which had optimized frame rates in the earlier missions, but poor frame rates in the last few missions and several bugs. We contacted Factor 5 and asked for all known issues and Julian himself replied with a detailed list, promising that the later levels were being optimized for frame rates, the bugs were being fixed, and that one aspect of the control would be improved. They said they would have a gold master candidate ready by our ship date, so I wrote the review on the assumptions that their promises would be kept, got the gold master candidate right before we went to press, and played that version for a few hours to confirm that they had addressed the issues. That gold master candidate was dated roughly a month ago, and as far as I know represents the game's final optimization.
I'm not sure what version the OP played-ours were never labeled "Preview Code", but a print mag's Review Code is sometimes a web site's Preview Code. Our last-received version of the game does not run at a rock-solid 30 fps, but I did not consider the frame rate problems to be an issue at all. I don't mind a few frame rate dips into the 20's here and there, if it's for the purpose of making an otherwise amazing looking game. I'm certainly not as sensitive to frame rate issues as the OP, but I don't think the average game enthusiast is either.
Just something to point out to the people who want to hate on Lair here-Sony and Factor 5 went all out to make sure the print mags got review copies as early as possible and frequent updates so that they could have reviews out before the game's release (which was at that point supposed to be August 8th, I think). Companies do NOT do that when they don't have a lot of faith in their games, so clearly both Factor 5 and Sony thought they had a critical hit on their hands, and any suggestion that they're trying to bury it or "send it out to die" is absurd. And having written the 9 review, I (obviously) agree."