It's actually a complex issue and not that frivolous. One of the things which is more apparent at Oxford than Cambridge is the different levels of basic teaching provision at the various Colleges. This applies pretty much across all of the main subject areas.
Most of the main Oxford Colleges employ full-time academics to cover their subjects. You should note, however, that there is, in practice, a considerable difference in exactly what is offered to students. In some cases, extra tutorials are arranged as a matter of course. Alternatively, tutors may offer ‘at homes’, essentially times when students know they can visit them with specific problems. All of this really depends upon the attitudes and commitment of the tutors concerned.
A word of warning specifically for Oxford. The PPH’s, in general, have significantly less teaching resource than the main Colleges. This is readily acknowledged in the University’s review of the PPH’s. Individually, they differ in provision but they are all short of the main Colleges in areas other than their ‘core’ (usually Theology, sometimes Law). Few students apply direct to the PPH’s. Those who are ‘pooled’ rarely realise that they are walking into an institution with generally lower teaching provision.
Understand, therefore, that teaching at Oxford is not the same for everybody. The Faculty for your subject will arrange the same lectures for all. Essentially, the Colleges (PPH’s) take it from there. It is here that the significant differences emerge. This is becoming more of an issue for students at Oxford who realise the extent to which teaching levels differ. It is therefore an issue of sufficient importance that you really should factor that into the equation when applying. The problem is, of course, that it’s very difficult to find this out prior to submitting your applications. Never be afraid to ask potentially awkward questions, however. After all, you will only get one shot at the degree.