I really would have loved to have these two projectors in house at the same time. The Planar PD8150 projector is the more expensive of the two, and the best of the recent DLP projectors I've reviewed. Neither is particularly bright, so they are very similar in that regard.
Both projectors have excellent black level performance, the Sony one of the very best, and the Planar, well probably very close to the Sony, and possibly its equal.
The Planar, though, does possess the sharper image of the two.
The battle for placement flexibility is close, despite the Planar's zoom lens not having as much range as the Sony. In reality, the Planar is the more likely of the two to be rear shelf mounted in most rooms, as for a 100" screen it can be as far as 17.4 feet, while the Sony can only be as far back as 16.3 feet. On the other hand, for ceiling mounting, the Sony can be placed substantially closer - only 10.1 feet vs. 13.4.