Rotostarts are pretty much same as drills, instead of a pistol type drill, its a straight one, with a dog bone shaft to turn a special gear on the backplate. Its still a geared motor powered by a recharchable battery, and yes they are slightly smaller than drills and you still need a glow plug warmer.

The eazy start works the same. The difference is the motor and gears are mounted on the engine, you just provide power to the electric motor and glow plug with a control module (switch) and a battery. This one though will add more weight to your car. But you will only carry the battery and switch and dont need a glow plug warmer.

Its just all about preference. They will all break at some point, nothing in RC is unbreakable. I broke my pullstart once, but now I know how to do it right. I have been using it for a long time and is still working just fine. Starts with in 3 pulls when primed, around 6 pulls when not. Like what the other member mentioned above, they do have their advantages and disadvantages its just a matter of whats more important for you.