pvr-250 vs pvr-500

[d94]

iv been presented with the opportunity to trade my pvr-250 for a pvr-500 strait up...i just bought the 250 for $60 shipped
and upon looking it up there's a $15 difference between the two!!!!
so, is there any reason i shouldnt do this?
i mean is there any difference other than dual tuner between the two..?

thanks
-d94