The rollover will most likely only kill if you decide to stay on the tractor.
Usually, without rops, if one is going into a rollover situation..........you jump to the 'uphill' side of the tractor(but ya gotta have the 'mindset' for this).
Rops will only save you if you use the 'seat belt' religiously, but you still may lose an extremity(arm or leg).
My attitude to a ROPS is similar to Don87's. I'm not arguing for or against ROPS, but decided it is not for me. I spent the first 6 or so hours on the new DK35 HST thoroughly testing it with the ROPS on every part of my acreage. It is much more stable than my previous tractor which did not have a ROPS.
I left the ROPS on for the first few weeks and then removed it because:
1. it needed to be lowered to fit in the garage. It was a matter of time before I would forget and tear off the door. My method of not forgetting was to partially close the door so I'd remember the ROPS when I returned.
2. the ROPS was a hazard on my winding trails and while gathering wood. It snagged a couple of small branches but the possibility was there that it would snag a larger one.
3. I would have never used the seat belt. I am on and off the tractor a lot, moving tree branches, rocks, and cutting wood. As I write this I realise how silly I was with my ROPS testing as I did not have the seat belt on.
It's a personal choice. For me, the advantages outweigh the disadvantages and I hope I can continue to exercise prudent judgement to safely operate the machine with no danger of a rollover. I know I'm not agile enough to rely on Don87's method of jumping off on the uphill side.

Others will make a different choice.
I think some of the safety stuff is overdone. I actually feel guilty removing the ROPS, but have never once felt like I needed one.
Another example: I'm a former lineman and still have my old belt and spurs from the 1970's. I use them to climb trees while felling or topping, and for climbing the odd pole while helping my local wireless internet provider. On two separate occasions he told me my belt is illegal because the Govt Saftey regulations call for a 3 point harness. Totally ridiculous! A more reasonable regulation (which I'd also ignore) would be to ban old crocks like me from climbing poles and trees.
I'm not arguing for or against ROPS. But we can probably all agree to operate safely and have fun.:thumbsup: