What was your PB previously?
41:49 from last November, since when I have done no speedwork except that in the marathon training schedule. Unnecessarily disappointed to find last night's race was ARC not UKA so does not appear on RunBritain!
Personally, I think 'testicular status' falls definitely in the 'too much information' category...
Interesting debate about pacing. Myself, I have never run a single run- even the slowest recovery run- without my Garmin since the day I bought it. I certainly would not want to be without it in a race. I could imagine maybe doing a 5k without a watch, but even at 10k I like to know how fast I am going. There is something to be said for going out fast and hanging on in shorter races, but I wouldn't want to be doing it in a marathon.
As Fraser said, often marathon pace is dictated by an artificial time target, in which case you know months in advance what your required pace is and train accordingly. This is what I did. If you had looked at my HM PB from last year, it was at 7:15 pace, but I was determined to get GFA requiring 7:25 pace in a marathon, so I set all my training paces for this, and luckily it worked. Getting my HM PB down to 6:50 pace also gave me the confidence.
Also interesting to read Martin's thoughts that you like to have a target time in mind, as you appeared to approach it from the opposite direction this year, successful training leading you to revise marathon pace downwards as the weeks went on. IIRC Martin you did not do a HM in the build up- I feel I really need this to judge potential marathon pace.
Speedy- as a much older (and I suspect more novice) runner than you I approach it from the point of view that there are a limited number of marathons I am ever going to run and expect to improve my PB, so I want to aim as high as I can. Right now, with a 3:13 PB, I am certainly thinking that if I stay injury free I will aim to get as close to 3 hours next year as I can, and if I am anywhere close, I plan to go for it. In your defence (if I have stalked you correctly) your conversion across all your PBs is very good- 88 HM to 3:08 marathon for example.