Few and subtle.

The device on light is light blue on the normal tablet, orange on the WiMax. The default theme is also orange instead of blue. And the keyboard. Black and orange.

It has the bump for the wimax hardware, and it feels like plastic, not metal. The car mount has space for the bump.

There is of course WiMax support files and entries in the filesystem and dialogs.

I haven't tested things in depth like sensitivity, but I haven't seen much difference.

The best buy price is only a bit more, so is there a reason to go if there isn't wimax? Well, the color is more in keeping with my Harley motorcycle. And if WiMax ever comes that will be an option.

I use an EVDO modem on a Cradlepoint PHS. It is slower than WiMax (1-2Mbps v.s. 3-4), but also will go down to 1xRTT (144kbps) in remote areas (there are few with zero coverage).