Drilling rigs have more opportunity for advancement and the experience can transfer over to more higher up jobs than service rigs. But service rigs will teach you way more about what goes on downhole after they drill it. Drilling hands are usually pretty ignorant about completions/etc... and vice versa I suppose.
I've worked both, so this is first hand knowledge.
Service rigs is harder work. Both physically and mentally.
Service rigs work more hours per day than drilling rigs
Service rigs dont have scheduled time off. When you get time off, it can be as little as one day.
Service rigs get you dirtier, colder, wetter.
Both are full of douchebags, assholes, sketchy people, etc. Neither one has a benefit here. People from all walks of life love the promise of free food and board on a drilling rig. lol
I personally enjoyed my time on the service rigs better, but I had an awesome crew and we worked together for years. Stayed busy, made money.
And thats the other thing, there is no guarantee of work with either.
I can eat more hot wings than you.