Video:
The R1 has a higher bitrate and is a little cleaner without being overprocessed.
Audio:
R1 audio is much clearer.
Subs:
In some places they're identical, in others they're not - usually when the R1 gets a bit colloquial. I prefer the R2UK's subs although they don't cover everything, the odd word or phrase is not subtitled but it's not too important.
Extras:
N/A
Overall:
R1 - £30 buys you five good films and all with good transfers.