In short: Needs Improvement but not that bad. In full: Well I have read some of the other opinions and as this was my first London 10k it was not that bad.
You have to remember that this is London on a Sunday morning and they want to have the roads opened as soon as possible after the race has finished as the shops open at 12:00 and thousands of people will be driving in. Therefore the bag drop area is the best place as it has a minimal effect on traffic well after the race has finished and the rest of the course can be cleared as the race progresses.
Yes there were a lot of people around the bag drop area and toilets but for those not proud just head up to Green Park where there are plenty of trees. I queued for 20 minutes but as the start is about a mile away jogged all the way which was a good way to get warmed up and use a tree in Green Park.
It is not a PB course as there is no way they can make holding pens for your expected finishing times so you have to weave in and out of slower and “why they bother” walkers in the first 3k. I was only 53 seconds out of a PB.
The walk back to the bag drop area was welcome as you need this after the race and the snack in the goody bag was welcome as well as the Red Bull and water being handed out.