Toshiba SD-3900 vs Toshiba 2900

[scottp120]

I have a Toshiba SD-3900, but my parents are looking for a plain DVD player and saw that they have the 2900 which is $20 or so less than the 3900. I know that the 3900 can't play VCD's or Photo CD's, but is that the only difference besides the optical digital output and progressive scan? They're going to hook it up to an old tv so it doesn't have to be the best DVD player out there, I just don't them getting a piece of crap like an APEX or DLH $40 player.