It is your choice as to weather it is worth it or not. We have had DirecTV for over 10 years and have never paid for their service "protection" plan. To us it is a waste of money, I'll gladly pay the shipping if I need a replacement unit. Other say it is best to pay for it. So it's your choice.
You will get a lot of different opinions on that question. If you like to "do it yourself" you don't need it. If you want a tech to come out and fix any problems that arise it's a good plan. If you have a box replaced without it you pay shipping and restart your two year commitment. With it shipping is free and no additional commitment. I live in a very windy area but have never needed a dish alignment but if I did it would be covered. I hope some others will chime in and give you their ideas.
The protetion plan essentially covers everything related to your sateliite system. The dish, the cables inside and out, remotes, etc everything.
Dish gets hit by lightning and blows your recievers and melts the dish, it's covered.
Dog chews the hell of your remote, covered.
Dog chews the cable in half outside or you nick it with the weed-eater, covered.
Without it, service calls run $75 a pop for our area. Doesn't matter how big or small the issue is, whether it be a connector or re-programming the remote if the customer accidently gets it out of whack.
Receivers are covered under the lease with or without the DPP but I think you still pay the S/H charge.
Up to you if you want it or not but that's what it is. I'd keep it for a year at least, things tend to go wrong more often than not in that first year. Dish gets blown around, an improperly sealed fitting gets water in it etc.