It was nice to briefly run with your and put a face to a shell, I think the 3:15 pace group were more than 3 minutes up, I ran 3:07 and on every switch back they were on my heels. Given that I slowed towards the end they should have been been at least the same distance behind me as the 3:00 group were in front, it wasn't even close.
As you say, perfect weather, great crowds, even the power station stretch had some support this year.
I hated the weird bags of water 2 years ago and the cups are an improvement on that but still a lot worse than bottles. I got more water up my nose than in my mouth whenever I tried to run and drink so after the first few I started stopping at the end of the water station. Gels at 5, 10, 15 and 20 was great too, no need to carry any myself.
One tiny bottle of water at the end on a hot day was totally inadequate, good range of snacks in the bag and nice to get a technical tshirt. Generally a good event and I'll probably do it a third time.
Michael (18 week 55-70, approximately 50% of runs managed after the first 4 weeks due to family stuff).
The blank is linked from the rules page on their site, http://www.maratonadiroma.it/PWA_uploads/facsimile-certificato-medico10apr.pdf, you'll need to pay your GP to fill it in. My GP has always been fine with this but some others on here have reported problems.
It looks like this year you also need a runcard, whatever that might be, you might find it easier just to join an affiliated running club.
Hill1 - I usually do Edinburgh plus one other spring marathon, this year, like you, I did London. Edinburgh is always late so the gap is big enough that your legs will be fully recovered but small enough that you can basically rely on your fitness from your earlier marathon (there's not really time to get more than one proper long run in between your recovery and taper). I don't think I have ever managed to improve on my previous spring performance in Edinburgh and I won't be trying this year, I'll probably run around 10 secs/mile slower than I did in London and try to enjoy it.
P&D says "These sessions are done after a thorough warm-up and often towards the end of a general aerobic run or recovery run. Allow yourself plenty of time between repetitions so that you can run each each one with good technique... A typical rest is to jog and walk 100 to 200 metres between repetitions."
Personally I run them so they're all done in time for a 1 mile-ish cool down, 100m on, 100m(ish) off (just linearly as part of my usual out and back runs, no backtracking or messing around on a track).