Hey guys, nice comments and observations. I got pretty serious about these two rackets too, and I agree, the x-Blue 94 was my favorite of the bunch. The x-Black 94 was my second choice, but not quite as comfortable and solid as the x-Blue 94.
I also found the Dark Red to be a bit insubstantial. Again, the sweetspot on volleys was very small (probably looser/softer strings would help). It was nice but seemed more like a toy than real tool. I guess good for 2.5+.
The Blue felt solid as a rock and I could put the ball on a dime. Since I was demoing, I was playing with the "provided" strings which seemed too stiff (given the rather stiff frame/material) which caused some trouble with feel on the volleys and a very small sweetspot (and I've played with the PS85 for years with no trouble) plus a "tinny" clank to the frame. Because of the high cost of the racket, I didn't want to shell out the dough just to see if some softer and/or lower tensioned strings would turn it in to a solid, smooth and accurate stick. I'd love to give it a try again, but at this point I've gone a little lighter with a Wilson BLX 95 Team. Nevertheless, the Donnays are wonderfully conceived and beautifully made - a real quality frame.