@MrWilde - yeah, I've had various fancy display setups in my time too! My best was 7: 3 displays, a portable display, an iPad (using Duet), an iPad Mini and an Android (though technically, the last 2 were just site sharing) :P

Unfortunately the problem is not the number of displays, but the densities of the main desktop displays. I suspect that if you're on a modern laptop the density is by-default going to be at least double, so adding normal displays appears to make Windows sh*t a brick.
Check out this example for Windows' own tooltip displaying double sized, along with the cursor:
Or here, Windows' own File / Save dialog displaying double-sized:
Or here, Adobe Flash not scaling on a high-density display, so everything is so small as to be unusable:
Urgh. Total car crash.