CEV, like you I switched from DTV to Dish over 2 years ago. It looks like you're already scheduled for the install, but I wanted to share my experience with you. I switched to Dish because I was having recording issues with the first gen Genie. Other folks were having the same issue, but DTV would not acknowledge there was even a problem. So they lost me as a customer.
Like most everyone else says the Dish equipment (DVR) is superior to anything else I've had. I have the Hopper 2, or Hopper with Sling, and it's worked just about flawlessly. I record a lot of programming! With Dish you can connect an external drive for expanded storage, but the great thing is you can connect it to any DVR on your account and watch the content. So if you upgrade or if your DVR fails you keep the content on the external drive. Also, you can transfer recordings from one DVR to another. So, if you want to upgrade you don't lose all your recordings. No other service that I know of, even TIVO, has those capabilities.
The one issue I have with Dish is their picture quality. This is VERY subjective, but to me, DTV (and Comcast I had previously) has better PQ than Dish. Many people say they can't notice any difference. But if you search the forums there's enough chatter to know it's not just a few crazy outliers. On the first page of this forum there's a recent post about Dish's PQ. I'm an AV nerd, so PQ is very important to me. I pay very close attention to it. The day it was installed I immediately noticed a difference. The PQ has improved since I first got Dish though. The biggest improvement was when I upgraded my H2 to the new carbon GUI. Right from the release of H3's people remarked the PQ was better. So you'll be at a better starting point than I was. And you may not notice a difference, which would be great. I'm not telling you this to deter you from Dish. I'm out of contract and I still have Dish. The equipment reliability and performance mostly out weighs slight decrease in PQ. It was just a surprise (and somewhat a disappointment) when I first got Dish. Wanted to 'warn' you ahead of time.