We happen to have some NetApp filers for other reasons, so I have my ESX disk images stored there, but if we didn't, I wouldn't think twice about installing a generic x86 machine as an NFS server. I'd probably use Solaris as opposed to Linux because I'm happier with their LVM solutions, but NFS is solid.

Then again, I'm not a big fan of having someone to blame. It's pointless. Even if I could (or wanted to) point my finger, I'd be the one who chose them in the first place. Support, though, is a different story, and I can understand the desire to have an expert on call.

I don't know what you're intending to use ESX for, but I find it to be far more useful for Windows machines than anything else, because running multiple things on a single Windows machine can be a bad idea, and then you end up with a bunch of machines vastly overpowered for what they need to be doing. With VMWare, you can effectively have a bunch of really wimpy machines combined into one or two physical servers.