- s2-like lighting in a7? -no, not even close
- bv fps slower than same scene a7? -no truly comparable demos out there, but wait until gameCore 2 is released (shortly, some weeks), but i truly doubt tobias' statement
- s2 is a first person shooter engine, and if you don't invest your cash in the whole pro package, you won't be able to pull off anything else than shooters
- s2's scripting is still limited, so is their model file format support (yet), you'll still need 3ds max for animated models
- gameCore2 seems to be the most user friendly and complete package with a great variety of supported files and an easy scripting language, but it's not available yet and you can only guess about its performance

if you are looking for a cross platform solution with great lighting and the possibility to play your games in a web browser, try ShiVa/Ston3D