How often do mariners leave drilling?

Would anyone be able to speak about their experience going the other way, (from OSV’s to Rigs)? It seems to be in the back of a lot of guys’ heads that I’ve come across on the OSV side.
As far as benefits, pay, crew changes, and overall happiness? Some are very worried about extreme boredom after having been handling boats and having a lot more hands on action that makes the time go by a little faster. To go from a position like that to say, a DPO on a drillship, might be a big culture shock.
Has anyone done such a career switch that has regretted it? Or is it just the opposite where the pros would outweigh the cons to a point where they were happy with their move?