Found driving with a screen to be better than I expected - not too much buffeting - but I really need to wear some ear plugs or ear defenders to protect my lugs from wind noise.
The CBR-style mirrors are excellent, clear and rock-steady, but the Halfrauds stick-on mirror vibrates far to much to be any use. I have a query elsewhere about that.
All in all I'm pleased I made the change - I know it's not as aerodynamic now, but it's great to drive without a screen.
One thing I've learnt though - Leave off the screen before the IVA, but do all the preparation as you're building (fitting the wiper mechanism, and so on) because it's much easier to do it while everything is in bits, and a lot harder to do it later on. Once it's all installed and working, take off the screen and stuff and use rubber plugs etc. to make the holes neat, tidy and to give no impression whatsoever that you'll be fitting a screen as soon as you've got your IVA certificate!
I'll be putting some extra stuff about how I fitted the screen on my website once I've got it all organised.