NB
I did my first 10 hours on C150/2 and finished it on a PA28. A few hundred hours later I fly a Beagle Pup.
The C150/2 is a better trainer than the PA28 (which is just too docile), but I imagine that the Robin would be similar in some respects to the Pup.
Once you have got used to the crisper handling (which will feel very different to the SLMG), your flying will become more accurate and you will love it.
Whatever you choose, enjoy!