I have had all three (D, E and Comcast) in the last 8 years.
Picture in order
DirecTV
Comcast
Dish
Some people say you can't tell, but I could always see that Dish HD was softer, I like a nice sharp picture and both DirecTV and Comcast gives me that but D* is a tad better.
Never had the Hopper, but the X1 works great, the storage space has never bother me since so much is online like HBO GO, Showtime, Starz, we only record shows from the Networks, AMC and FX and a few others.
As far as price goes, make sure you tell them them you have Dish now and they will give you a better deal and if you agree to a 2 year contract ( and their prices stay the same for 2 year unlike the Sat. Companies that jump the 2nd year) they will give you a upgrade or two.
For example-I have the Starter Package with HBO and Blast Broadband, they gave me (to keep me from going to U-Verse) a upgrade to Extreme 105 and Showtime and Cinemax ( we have Starz free from a mistake they made ) for a $1 each a month all I had to do was agree to a 2 year contract, all I pay is $106 a month which includes one X1 box and one HD DTA box, we own the Modem so that saves $10 a month and our price stays the same until March 2017.
I am always amazed at what people pay for Sat. TV service only, I see people posting how much their bills are and usually it is more then what I pay for TV and Broadband.