Thought I would add my impressions.
The Viper has it's pros and cons. The exterior model looks great. However, there is only one texture. I don't have any FDE issues with my setup, but that may be how I have my sensitivies set.
I only found two animations: the canopy and folding blades. Would like to have seen some more.
The 2D and VC are not bad. Glass cockpit is readible, but not the best. The HUD is quite nice. Works quite well in 2D, but hard to read in the VC unless you zoom in. No framerate hits with this one. As for the rest of the cockpit, not all the switches are clickable. I've never been able to figure out how to set the Heading or CRS direction.
Bottom line (for me) its not bad for $20.00. It could use some tweaks, better documentation, and a lot more textures to really be enjoyable.
--WH