NQ career path advice, off-shore v Regions

I recently qualified in corps in an international firm (think DLA, Eversheds, etc) and I am looking to move firms but having trouble due to the market conditions. I have also qualified into a regional office which is a hinderance as my goal is to move to London. However, the quality of work we do is very good as I have worked on large deals and fairly complex restructurings.

I have been offered an interview with one of the large off-shore firms which is attractive because not only would I work on transactions but I would gain experience in funds and finance. Ultimately my goal is to get to London so my question is would it better for me to stay at my current firm until I am 1PQE then look to move, or shall I take the off-shore role (assuming I get it), work there for 12-18 months then hopefully get a move to London?

I have seen a fair amount of associates who have done this career move and then moved to top calibre firms at 1-2PQE.

In terms of salary the off-shore (after tax) works out to be about £1,000 more a month.

Thank you for reading and I would love all opinions.