The R-22 is cheap, cheap to operate, has good parts support, but does not have the best survive-ability in a mis-hap, and has a tiny safety envelope.
The 300 CBi has a huge safety envelope and in my mind is a better initio trainer, but costs more, and parts may be a problem.
I suspect if you ran a risk analysis on the issue, the 300 would win.
I personally will never get in another Robinson, and before the bashers come at me.....yes I have flown it--I have over 4,000 hours in the R-22 in a former life.