There are numerous reasons of why you'd have bad service with sattelite but I can tell you that at least in every place I've lived, the benefits of dish and directv FAR outweigh the fractional times I lost service.
The biggest issue is line of site obstruction. if you have a CLEAR view of the southern sky you would have great service with sat TV (dish or directv). There is also some stuff with what's called the eastern arc that will help questionable positioned homes.
I have dish here and had it in phx. also had it in san diego and LA. I would lose service at times of extreme weather, but certainly not regularly. If you live in a place that snows a lot it could get worse, but they also make covers to go over your dish to displace the snow collection.
I would say that on average, I lose service for less than 5 hours combined per year. Most times it's very brief.
On to the next. Cable tv can't hold a candle to sat packages. the HD content is overwhelmingly favord in satellite.
the other part, is the dvr boxes. Dish network has the best DVR I've ever used. the ones I got from the cable company both times were just awful. No features, couldn't even sort recordings into groups, single tuners etc. With dish I can record 2 shows at the same time while watching an OTA channel as well. it also has 500gb hard drives, AND you can attach a USB external drive for extra storage. I get a little over 200 hours of recording time on the internal drive, and about 150 hours extra on my external drive.
Sounds like overkill, but I don't ever watch tv as it's broadcast anymore. I record everything. I don't ever see commercials that way
I won't be using cable again anytime soon.
I also have my box connected to my broadband, so I can download on demand movies, and even 1080p on demand.