Hmm. I wonder if we're thinking about the same rad as this one is very thin. It's from the quiet power series. The RX240 is twice as thick. Good point about the fans, though. I'd forgotten that we have a pretty thorough testing ground here for 25mm fans.
About the RZ bit-- it's the same one you've seen me cut with in all the pictures. It's a carbide milling bit from Bosch--much stouter than the bits that come with the RZ and cuts much quicker. Looks like a drill bit except it has a flat (not pointed) tip and the cutting grooves are sharper.
Edit: Thanks for the link. Reading now.
Edit 2: Well, it looks like I'll be canceling the order for that other XSPC RX240 and the thin fans and just going with some good 25mm fans. Thanks shazza! Really surprised at the MCR's performance in skinnee's testing. Had no idea it was that close.