I've used virtually all of the iDRACs. They're probably in that 200ms area (based on my gut feeling w/ no empirical measurements). They've been fairly responsive in my experience.
> -Remotely mounting images (ISO/FS/IMG/etc) on the host for bare-metal installs or any other purpose
For what it's worth, that stuff has always been incredibly unreliable for me. Enough so that old school PXE booting was the only way to maintain a server pool, couldn't get them to consistently reimage through the proprietary stuff.
The remote power control is very nice, and I didn't see anything on this page about that. (Though now I'm just imagining the "useless PC" [1] that just tells a smart power plug to turn itself off.)
I never had a single issue with it if I mounted it from an onsite drive. Mounting from home in my den is a bit more iffy and pretty slow. PXE is definitely better, but the iso method is nice for when that's not an option.