Hi,
I have used both and found them very good, the R&G are more basic but very good and a lot cheaper but had 2 sets of Oxford touring grips and they were also superb. Not much help really but if on a budget i would go for the R&G. I got a good deal from the bike show a few years ago so maybe worth waiting if you were going anyway.
Another brand to seek is Daytona. I got a set in the Hein Gericke clearance sale at a good price.
A mate has R&G on his Pan and is happy with them.
Oxford work but they are dearer as they are more sophisticated.
If price is important get the R&G - they have a Ride best buy award. If you want a fancier control and don't mind the extra price get the Oxford ones but check out the price of Daytona as well.
The important thing is to wire them into a circuit that is only live when the engine is running. My current and last bike (both Yamahas) have fly leads ready to connect into if not using the OE grips.