I've had both - started with DTV but now have Dish.
Customer service was one reason for getting rid of DTV.
Getting HDTV with my satellite dish was another.
If you don't care about HDTV and if you're going to be a full time customer, they're about the same.
When I had DTV, I owned my own receiver and could activate/deactivate service when I wanted.
I'd pay a daily rate, about $2/day. Great for weekend trips
The hassle was getting DTV customer service to understand this when I shut the service off.
They'd always charge me for a contract cancellation fee ($400) when no contract existed.
With Dish, they have a dishformyrv program which allows me to come and go (just like DTV) but on a monthly basis.
Sure I pay more now with Dish, but not having to spend 2-3 hrs on the phone with a DTV CSR is worth it.
Most of their CSRs are new, and don't understand all of the services DTV offers. (They're trained to zero in on the 2 year contract)
Plus, with Dish I can turn service on/off via web. DTV you cannot - you have to talk to someone.
Make sure you really don't want HDTV, because if you do that could make your DTV vs Dish decision for you.
DTV has HD channels on KU and KA band, which means you'll need a bigger, heavier, more expensive satellite.
Dish has HD channels on KU band, so a smaller, lighter, cheaper satellite.