To be honest I went to oxford and would say between the two go to the cheapest because they will both get the job done
I personally preffer the Oxford notes but others find the Bristol ones better for them.
I was the same commuting in to do courses etc and getting to oxford is way more simpler than Bristol although with the expansion of LOC's at Bristol it may not be the case now.
There isn't much difference between the two they both get the job done. Although you can get buggered around with the exam centers with oxford because the full time students tend to book the exams months in advance in oxford so that center is full up and you have to decamp somewhere else for the exams.