Driving accuracy will not be helped by the RII driver. IMHO it edges it overall over the L81 G20 but no forgiveness - why many say bad stuff about it?
The R11 iron set have a faster meter, but nothing to be afraid of IMO. You have the L59 iron set, and so an improvement club wise IF the meter is OK.
I take it the driver is your main question going by the title and noting you have L59 Iron's currently.
Overall though your distance to the pin / putting is the bit that needs to be looked at. I know that is the area of my game I have been working on and need to continue working on. You are a L88 Legend, and so understand the game. Distance to the pin and putting are the main part's, and so what do you think there as much as anything.
Improving Your 5 foot putt's would have the greatest immediate impact on your game I suggest..............................
In Short the L90 Iron's, combined with the R11 driver is a good combo if you are OK with the meter and don't miss by much with that driver..........Apart from working on the green though it may be worth holding off until L90 and thinking again then - ?????? depends on how credit's are burning a hole in your pocket or not...