fvjuke
Sounds like your fps's are pretty good - again, even a constant 20 is "not" bad -
The "blurries" have been a problem to many of us. It's the processor trying to catch up - there's just so much info being processed.
Again, from my experience, the fps's were better with the "good" add-on's.
Strictly from my experience (and yes, I talk to NickN by pm many times - this guy is a guru when it comes to FSX and add-ons) -
GEXn, 1.06v , SceneryTech, UTX with all updated patches, - I would wait for REX to come out soon. I am going to replace my GraphicX (which is good) with REX, which is just phenomenal. Go to their site: think its www.realenvironmentextreme.com - will blow you away.
Installation: UTX, GEXn, SceneryTech - Nick tells you how to place them in order in your Scenery Tab or I will be more than happy to do so. Once loaded, you do not have to boot them each time.
Also, if you pm me, I will be happy to attach my "tweaked" fsx.cfg, which is a "NickN" and cthiggin compliation that has worked great for the past 3 months.
I have VistaHP but do NOT run in DX10 mode, which is still in it's infancy.
My specs: Q6600 Quad, XFX 680i MB, 4 Gig OCE Ram, SwiftTech H20 Liquid Cooling, Raid Stripe 128, O'clocked to 3.6 ghz, memory overclocked, GTS 8800, overclocked. - STILL, FSX will bring it to it's knees under certain circumstances, such as using Ultimate Traffic 2007 with slider set more than 60%.
Hope this helps.
cthiggin