Harmony Remotes - Old models vs current ones?

Some people like the older peanut shaped models...like the 620 or 676 if you can get a good deal on one. IF not, the 650 will do what you want pretty well.

More info here:
http://www.avsforum.com/t/1440161/ir-strength-direction-harmony-650-coming-from-676

If you just want to save a few bucks, I think you'd be better off getting a refurb or open box of a current model (like from tigerdirect). Buying a used harmony is very risky. If the seller got it replaced by logitech and is selling the old one, then logitech will disable it in a few weeks, and the orig seller and your money will be long gone. Unless you can buy from a friend, I wouldn't risk it.

Older models are better in some ways (more devices, more IR LEDs, etc.), but they're also worn out. Harmony's buttons only last a few years.

Having said that, my $15 RCA RCRP05B runs circles around any harmony I've ever had. The URC WR7 is another cheap model that's well liked. Both do activities (macros) just fine. Even your cable remote can usually be made to work like harmony with the addition of a programming cable and some free software.