The x1800xt is a cracking card at £170. I bought one last week. I was in the shop just about to order the x1900xt(x) when I heard the girlfriends voice in my head so I decided on the x1800.
To be honest, I made the right decision. If you have a 17" monitor it will be PERFECT. I have a 24" 1920x1200 dell widescreen and it's plays my games brilliantly. I haven't installed all my games yet because I've been busy on quake4. I have that on 1600x1200 because for some reason it won't go any higher and I haven't noticed any slowdowns at all
I was expecting it to be loud but it's not as bad as I thought. I have a pretty quiet system with akasa low noise fans and it's no louder than those.
I was very happy to find out that the sapphire model also has video-in so I spent all monday putting my dads holiday videos onto dvd
The money I saved getting the x1800 has been put towards a new headset, momo steering wheel (as I love racing games) and some other bits.