The two GTS250 cards arrived this week, so I installed them. I like them so much I have ordered another pair. Speed-wise they seem to be about 20-25% faster than the 9800GT while using the same wattage. Price-wise they cost about $20 more than the 9800GT.
On Wednesday I swapped the 9800GT card for a GTS250 in Luke. I did this one first as it has already had its power supply upgraded. After a reinstall of the drivers its off and running.
On Friday I replaced the power supply in Obi-Wan. I then put the other GTS250 in there. As with Luke I had some fiddling with the black plastic clip that holds the metal plates on the back plane. I ended up filing it back for the GTS250. After installing the drivers its off and running.
You can see the heat pipes from the heatsink in this shot and the fan. Its hard to tell from the photos (the plastic shroud gets in the way) but there is a heatsink between the circuit board and the fan. It is slightly wider than the heat pipes.