I did the 10 k run option this year, after doing the aquathlon last year (can't swim at the moment due to wound on leg).  This is a multi-sport event with races starting off at different times, the 5 and 10 k runs were at 1000 am.

Registration was easy, you can collect your number the day before (did this as local to me).  However, the timing chip wasn't available until the next day, but there was no queue to collect this.  There's no official baggage storage (most people leave these in their cars or in transition), but if you've come by tube/bike for the run you can leave it under the stairs by registration.

The race starts by the lake, with the 5 k (one lap) and 10 k  (two) legs going together.  There were only 26 in the 10 k, so it's not too crowded.  The run initially goes around the lake, and then loops around the Merchant Taylors school sports field.  It's funny going past the pavillion whilst the criket teams are warming up, last year it was Middlesex and Sussex 2nd XIs there.  The grass surface is good for running and there are some nice long straights.  However, quite a bit is unshaded, so it can be a bit hot on the run.  You then head off for a second loop, and there is a water station as you start this.  There's only really support at the start/end/transition area, but the marshals around the course are all very good.  The DJ is enthusiastic as well.

The medal is decent enough for a budget event, and a bottle of water is handed to you at the end.  There's a nice atmopshere and feel about the event, there's still a lot going on as people are coming in from the bike and tri events (having runners doing the 70.3 tri overtaking you at speed is quite humbling).  

As there are permanent changing facilities, there's quite a few toilets available and the upstairs cafe/bar is lovely.  There's a reasonable amount of parking available, and not too far from the tube station at Moor Park.  

All in all, it's a nice small multi-sport event, would probably do again as it's local, but may tri the aquathlon or swim next time.