I don't have any FSDT airports, so I can't say what the framerates will be if you use them. I have higher settings in P3Dv2, than I do in FSX and I slightly better, framerates (about 5 fps more) in P3Dv2. I have it casting shadows on itself, on the ground, in the VC, I have the clouds casting shadows on the ground and being reflected on the ocean.

As for the performance of the 777 (FMC, AP/MCP, LNAV and VNAV), it seems to be pretty much the same as it is in FSX. I definitely prefer to use the 777 in P3Dv2!