Networks What to look for in Cable Modem? Thinking linksys

I'm thinking of getting a linksys EtherFast Cable Modem (hopefully v.3) from my local computer shop instead of renting from my ISP. (16 months=same price as my own modem)

I'm purchasing my own because I like the idea of having more electronics, and my cable ISP doesn't offer a rent-to-own... its just a flat rate to rent with no perks. (Upgrading modems costs extra when new hardware comes out)

So I'm probably going to go buy this bad boy tomorrow, any tips? (such as "NO DON'T BUY THAT!" or "Make sure you get this version...")