ESXi doesn't recognise USB devices
I understand it has a USB internal support so it can do usb over tcp (something I'd never heard of) but directly connected usb devices per se are out. And I need that, no arguments, which is why I went for vmware server 2.0.2 (which I like very much, crappy webulous interface aside) [*]
@AC 08:49 - had a gander at the site to try to find out, it's a good question. Couldn't find anything. I guess it scrapes your real machine into a VM image then installs ESX then packs the image into ESX but seeing as VMware doesn't know what a website is for, I can't be sure.
Seriously, their web site is easily the worst thing about it. Trying to infer useful info from between piles of management bull is a mass slog. I spent days on it. You can find normal humans in the forums though.
[*] important note if you run server 2.0.2, sometimes a host service dies and the interface gives no useful info. You need to start it manually, and I suggest setting it to restart automatically on failure, something they stupidly didn't do.
Other note: running a DB inside server gives normal performance reading but about 1/3rd performance writing. Presumably on a bare-metal hv it would be much better.
Also I understand ESXi doesn't support much by way of graphics hardware. It really is boring reliable headless server stuff, not for home use, whereas server 2.0.2 arguably is (and I totally recommend over virtualbox for anything nontrivial; Vbox has given me too many headaches & got dumped).
Also upgrading a VM from vmware server 1.0.2 (IIRC) to 2.0.2 didn't always work reliably, trashed an image. Be warned.