Launching single handed is not difficult in good conditions: decent slipway, somewhere to moor the boat while you park the trailer, and no queues of people getting pissed off while you block the slipway!
Recovering takes a bit more practise, but providing your trailer is set up right for the boat, and you get it the right depth into the water, it can be quite simple.
If you're doing it right, then it's not more difficult in a larger RIB. In fact with the extra weight and stability it may even be easier.
It can be very satisfying and looks really cool when you get it right, but there is plenty of scope for getting it all wrong too