3:24:something!!!
Thanks
In the end, despite scorching weather and many more hills than advertised, I smashed my PB and came in at 3:24ish!! :d
Still waiting to confirm my official time, my garmin says 3:24:26 but this will be a couple of seconds out.
So overall, closer to my "nice, but you'll never get it" dream target of 3:20 than my actual target of 3:29:59! I'll have to run another this autumn, somewhere cooler, since I'm sure I can keep this going.
Pretty frustrating, I ran the first half in about 1:42 but kept getting overtaken by the 3:30 pace runners, often storming past me when I was doing 7:30 minute miles! Don't they keep a regular 8min mile pace? Or do they like to get "creative"?
A couple of slow miles at first, swerving around people. Finally settled into a rhythm somewhere around mile 6, lost a little time not too much. Tried to keep it steady after that, kind of hard to estimate my real pace since my garmin was talking out of it's beepy plastic arse most of the time, giving me pace readings of 3:20mins / mile and 9:30 all on the same steady pace...

But got to half way about 2 mins behind target, so not that bad.
Good going after that, hot but not too bad, lots of shade, fairly fast. I took on decent amounts of gel and water, put in some good miles. Quite a few short inclines, and some long stretches with no shade, but not terrible. Around mile 20 I was actually tempted to go faster, I felt strong, and was raring to go! But I kept it fairly steady still, planned to race the last 5k if I had the energy. Hit some hard miles around 23-26, mostly because of the 20degree heat! But rarely dropped below 8mins / mile, a little worry about thigh cramp, but this never happened in the end.
Around the end of mile 25 I just had to take a pause by a water station, grab a couple of drinks and walk for a couple of minutes, trying to rehydrate and cool down. I felt that the heat would make me dizzy if not, also fairly low on energy at this stage. But with everyone else keeping up the pace, I got back to it and, although I couldn't race the last mile, managed to keep around 8:10 until the final stretch, sped up a little, and overtook a couple more people in the last few metres
On the whole, I was really pleased; I cracked 3:30, decisively, despite hard conditions, and felt that I could have had a try for 3:20 with cloud cover and less crowding at the start. But that's for another day.
Anyway, off to rehydrate with another beer...