Well, they are both different, but if you take a couple of lessons with an instructor in an R22 you should be fine.
In my experience my students that moved from the 22 to the CB300 had an easier transition than the guys that came from the CB300 and moved to the 22.
But hey, they both have a main and a tailrotor, so it can't be THAT different ;-)
The important thing is that u get your proper training on the Robi (but that's the same with every helicopter)
Don't just hopp in and fly it, (i guess there is no SFAR73 in South Africa), and you will be fine......
Robi is more fun anyway