iPad 4th gen graphics issues with some 3D games

We just got a new fourth gen iPad with A6X chip. Previously we had a 3rd gen iPad with retina display from earlier this year (A5X). Since I can have them side by side, I decided to compare the performance of some 3D games on both devices. Games tested include NFS Most Wanted and Air Supremacy Storm Raiders, both very recent games.

With Most Wanted, buildings/poles/cranes around the track did not always display properly on the iPad 4. They would slowly appear into the background only as the vehicle gets closer to them. On the older iPad, buildings loaded properly and did not randomly appear mid-race only. In the case of Storm Raiders, plane turning and manoeuvres don't see as smooth on the newer iPad, there are more dropped frames and some light choppiness. This can be fairly subjective, but I'm confident the older iPad didn't have any issues rendering the game. There is no difference between the two iPads when playing "2D" games like PvZ etc.

Anyone else experienced this issue? Is it because devs haven't had a chance to optimize their games for the new hardware or because of a faulty device? Note that general speed when browsing and opening apps are always faster with the newer iPad 4. Geekbench scores are also significantly higher at 1789 on the new one and only in the mid 700s with the old iPad with A5X.