P7 is working great for me and I really want to keep it that way, i.e. unbroken.

But, P8 looks to have a better renderer and better multi-core functionality so I would like to increase the quality and speed of my images.

Can I keep P7 on my c drive and install P8 to an external drive without any problems? So I stick P8 on a Seagate USB drive and port over my runtimes to P8. When I want to use P8, i just plug in the drive and load it up and when I don't want to, I just don't plug the external HD in and P7 works as it does right now.

So 2 things i want to know:

1. Will my proposed setup work without any issues? I heard there are some issues like V4 doesn't port over when you import runtimes to P8?

2. Is the improvement in the P8 Firefly worth the upgrade? I don't go too crazy with lights, and hardly use reflections and shadows but I would use these features more if they rendered quicker (as in a few minutes for a 1000px image). The new renderer is all I really care about at this time. Maybe i should wait a while for a few service packs so the bugs are ironed out?

Thanks for your time.