Not trying for a vs thread... just seeing what's out there and what the pros and cons are.
I will likely download the free Unity and see what I can do with it and go from there. I like hearing from people that have done both as they have some experience that can be shared.
My knowledge with 3D engines is very limited at the moment, so writing one is a daunting task. However on the flipside, paying $1500 is also quite daunting for something I may not actually need. I understand a lot of what Unity offers but there are other things I'm not so sure what they are... for example... RenderTextures.
My target is a windows game. Would be cool to port to Mac OS. Trying to keep the scope small and build from there. If Unity can get that done for me easier, I may go that route.
However part of me wants to do my own 3D engine. So XNA would be good for that too.
Not an easy decision to make
I am indeed talking straight XNA. I'm not sure what the MonoGame platform is at this point.