Sorry Worf - you popped up while I was typing! But here is my bit anyway.
The Russian Forger fleet had an auto eject system that their mates told me had a 100% success rate at low speed and about 30 saves (some two seaters). Because in the hover the front was held up by two lift engines and the back by the vectored thrust main donk they had no option but to fire the seats on auto if the pitch attitude varied by 5 deg from that in the hover. By the time they got to the Freehand the seats were better and they allowed a 10 deg pitch change before boom. IIRC the roll figures were 10 and 20 for the two types. I would suggest the F-35 STOVL variant involves similar issues.
There is little doubt in my mind that the Russian seats are remarkable. Very heavy – I believe as much as 2-2.5 times MB seats- but remarkable devices. I can think of 7 airshow saves where other seats might not have hacked it. Anatoly at Paris in 89 being the first. Their seats have been multi mode for a long time and are cleared for high IAS and supersonic use - which has to be where a lot of the weight was needed.
Milt. I know of his case, but that is all. He was a lucky man and I think still the highest IAS MB escape.