$60 upgrade? you can just download a new flash rom for your current v90 modem man.
as for what v92 offers, fro what i remember:
- faster upload speeds
- takes much shorter to authenticate and connect.
- you can recieve and take phone calls while online, and your modem will hold your connection, so you dont have to d/c and dial again
- slightly better compression/error correction and the like
but for this to work, your ISP must support v92 as well.