He bowled well enough but so did Bhajji in South Africa. I would rate them roughly the same but the consensus opinion here seems to be that Swann is a lot better I just don't see the evidence. You can argue that a player's figures don't reflect his bowling in one series but over 2-3 years these things even out and Swann's record against top sides just isn't that impressive.
Anyway I am a lot more worried about England's pace attack than Swann.
Over the last 2 and a half years, Harbhajan averages 39.3 and Swann averages 27.9. That's a huge difference and even taking into account lower pitches, there clearly hasn't been an even performance over that time.
Swann obviously has a better record against less top batsmen - I'm struggling to see how this is a criticism. If Swann's figures accurately reflect the batsman he is bowling to, surely that speaks volumes about his consistency?
It's not as though he only gets out rabbits - his career list of dismissals includes Ghambir, Dravid, Ponting, Gayle, Amla, De Villiers, all on multiple occasions.
Swann has had two decent-to-good series against Australia and was MOTS in South Africa. He has consistently taken wickets and has five-fors against every opponent in the time frame I mentioned.
Harbhajan is a good international bowler, has just had a very good series, and still and may yet have a resurgence in the near future, but the argument that he and Swann have performed to a similar level recently just isn't true.