I am in a similar boat, recently moved to London and started my job-search about three weeks ago. I have been working through agents but also did a few online appplications through websites to PA, MoW, Cap Gem and ACN. So far, all I have gotten is system generated, "Thanks for applying we will consider you CV" from the online apps (except for PA - where I received nothing confirming they even got the app!). Through the agents I have already had three interviews (PwC, Deloitte and a smaller MC) and am through to final round interviews at Deloitte and the smaller co. My advice - use an agent!