For what's it's worth, we started off with a Carry Out on Dish and a VIP722K reciever. While it did work very well there wre some limitation but nothing we couldn't work around. Most HD channels were fine and the few we coudn't recieve the SD counterparts were OK so we didn't lose the program, only the HD.
This year we had BCS install a Traveler and, without a doubt, was a good investment. Much better reception and the ease of pushing a button, over setting up an external, made it worthwhile. Plus it opened up a ton of Bay storage once I got home and sold the Carry Out.
If you get something other than the Traveler, it's possible you will be spending the $$$ twice as you will probably get it later.