Its often hard to get an objective view on which ground school is best as 99% of people will only have the experience of one.
Personally I did Bristol distance learning and they were fantastic, they have been doing the course for a long time now and really know what they are doing. Bristol's notes were excellent and their feedback second to none. I understand people from other schools are recommended to sign up for bristol's online question bank. Have seen oxford's notes and they were very impressive as well. They are both schools that have been teaching the courses for a long while and seem to know what they are doing and what is required for the exams.
As to DL or full time it is often a tough call and really varies from person to person. If you can be disciplined and put the effort in whilst also working then DL should be managable but it can seem like an uphill struggle at times.