Easy to get to and very well organised. The organisers seem to work hard to engage with the local community, as a result the local support is fab, like the whole of Ealing comes out to party. As Peter says it is pretty urban and surprisingly hilly so although I enjoyed it and it is local to me I'm not rushing to do it again.
I agree Cal the Runthrough races are great I've done a few of their Wimbledon common halfs and the support at Ealing is second only to VLM in my experience. But this is a mass participation race bang through the middle of London on closed roads and it's never going to cost 20 quid. No one is forced to do it so why moan? I got in this year and probably will cough up, it was my first half a few years ago and for various sentimental reasons I'd like to do it again. I'm a slow plodder and big flashy races like these are sometimes fun to do too and yes hopefully I will pb which in my case is sneaking under 2 hours. And they do at least give you a really nice tech teeshirt which would cost 20-30 quid to buy.