Actually their PVR models are pretty good. Much better than Replay. It's also faster than replay.
I haven't used a Tivo, but why use something when something else works just as good ?
You haven't said anything that's good about the Tivo except for "Save your money, get a Tivo"
I can comment on the differences between TiVo and the DishPVR. I was a long-time cable subscriber with a Stand-Alone TiVo. Once I moved to a place that I could have a DBS dish I jumped on the chance to get it. I tried to compare Dish's PVR to the DTV DirecTiVos, but no one ever had them hooked up. Finally a salesweasle at Radioshack told me that the DishPVR was made by a different company but used the TiVo software. So I was sold down the river of lies.
I spent a year suffering through the POS known as the DishPVR 501. Through 2 replacements and a software upgrade the thing never did a good job of anything. For anyone who has used a TiVo, the DishPVR is the most frustrating interface of any PVR I have worked with. The search function is poorly setup and will often miss items that should have been found. The device will hang for no apparent reason and you won't get your shows. They don't offer a season pass feature which is the easiest and quickest way to catch all of your favorite shows.
If you want to see other pros and cons visit avsforum.com and tivocommunity.com
The real deal (IMHO) is from orbitsat.com. They're offering $69 for a pro-installed DirecTiVo system and DTV is offering 4 months FREE of Total Choice Premier (This is the EVERYTHING package, all the pay movie channels, all the sports, all but PPV) when you sign up and get NFL Sunday Ticket.
BTW, you can't even *GET* the NFL package through DISH.