Not to sound like a fan boy but Edius it's probably the fastest NLE until you stay within it's native tools. As you drop in the timeline an external filter or plugin the game is over E.g. As I use a magica bullet look I'm forced to rendering at each edit or look change. I hope that with openCL support my card will suffice for basic editing and grading.
Regarding the external grading monitor I think it's not a Resolve issue but a more general one. I have a simple Dell U2412M an IPS LED 1920x1200 16:10 monitor and most of the times my video looks completely different on other screens. Given that a new expensive monitor is not in my future right now I use to preview them on my tv and some monitor and eventually apply some correction prior of publication.
Right now I have a Intel Core i7-2600K CPU @3.40GHz, 8,0GB RAM, Intel HD Graphics + ATI HD7850 on Win7 64bit.
I'm able to edit my 140Mb AVCHD files straight into Edius without transcoding. I can add several filters and CC on several tracks and still be able to play in real time. Furthermore it's able to use Intel Quick Sync technology for H.264 hardware encoding so export process it's two/three times faster than normal sw encoding.
It's hard to leave it But I guess I have to bite the bullet and give it a try.