Welcome dvdguyjt :hi:
The Dishplayer is a little smarter (although buggier) then the 501. Lets say you have a show you watch every night which airs at 7pm. The Dishplayer will only record it if the name of the show is the show you want, the 501 on the other hand will record the show every night of the week including the night its not on, it just records by the time and not by the show title.
The Dishplayer has Internet access available to it with WebTV/MSN but the internet access is only work it if you already have a MSN account (then your WebTV access on the Dishplayer is free)
Up till a few weeks ago the 501 lacked as it had only a 2 day guide and had no search features.
Now they have 9 day guide and a basic search feature. The 501 is turning into a nice machine. It does have some bugs which are not anything major.