Can you do a trial week in the places before making a decision?

I'm a bit biased as I'm only ten minutes away, but definitely London Bridge. It's an extremely busy station (I was amazed at how many of my clients come via there when I'd just assumed most would be coming from Liverpool or Fenchurch St since I'm north of the river), plus you get the punters going between Waterloo and Canary Wharf and suchlike on the Jubilee Line.

As for run down or unsafe, I doubt it's any more so than Kentish Town, and there are a likely a lot more police and cameras about. I have a friend who worked there for years not far from the Shard and never had problems .

Thanks so much for the feedback Amy, to be honest I'm leaning towards Kentish Town because most of my clients come to London via Kings cross, also the London Bridge apt is in a council state run down area and it doesn't feel very safe at night. Client wise that is a problem. I'm also not that crazy about the area -in general- when it comes to living there and socialising, coffee shops etc.., I'm more into the "Camden vibe" sort of thing. Kentish Town apt is also cheaper, so I'm juggling the pro's and cons and Kentish Town is winning at the moment 

In that case I'd absolutely go for Kentish Town for my own safety and that of clients.

I've never been in the London Bridge area but I do know that there is a naturist spa in Kentish Town, I'm not sure what sort of impact that could possibly have on bookings.