Just picked up my 20' Wide Dell monitor last night. It looks absolutely stunning. I also pickup up the Radeon X700 I was waiting for, so I could play games properly (I was using the Geforce FX 5600). Installed the X700, plugged in the new flat panel, booted straight into Mandriva. As expected:
X failed to start. I was droped to a text login. Here's what I did:
Logged in as root. Ran # drakxconf, selected my new card as Radeon (fglrx). The system automatically started to download & install the ati & dkms-ati packages.
Once done, rebooted the system & I was back in X again. Again back to MCC to select my new monitor & resolution. The Dell E207WFP was not listed, so I went for the Generic Flat Panel 1680x1050. Restarted X & i was finally back in high resolution (after surviving 2 torturous weeks of 14' 800x600).
I had to give up using Beryl(it was getting distracting anyway), the ATI modules don't support the X composite extension required by Beryl and Compiz. I could use the open source Radeon module, but it lacked proper 3D performance. So I decided to use the evil propriatary closed source module from ATI.
Performance wise, the ATI card certainly beats the pants off NVIDIA. I can't easily compare the performance with something like glxgears (the NVIDIA was getting >4000 FPS, while the ATI was doing just >500) This is due to the way the evil ATI driver works. In actual game play (UT2004), the performance increase is very clear, I maxed out the graphics options, ran the game at native 1680x1050 resolution, not even the slightest hint of lagging. Awesome!