Yep, enjoyed that a lot. I'd pencilled in a 24 hour garage on the A420 (off route towards Swindon) between Durrington and Stow, but ended up not needing it.
It was good to see the sights: Glastonbury Tor, Stonehenge, Abbey Road, genuine doggers on the M4 underpass*...
(* apparently "real men ride women". Given all I could see were a bunch of glum men standing around waiting, perhaps it was more of a plaintive plea for one to turn up)
From there the ride into London was probably as good as you can manage, but I guess that is what you expect with a central London finish
I found Watford-Cricklewood to be an order of magnitude worse than anything I normally choose to ride on in London. South of Edgware was gridlock mid-morning and required loads of dangerous filtering.
Aldenham Road, which broadly parallels the A41 section can be lovely and empty. You just have to choose the right roads.
Two riders had bike reservation problems
I made my reservation over the phone and didn't have anything printed and they insisted this would be fine. Some officious dickhead at Paddington demanded I go to the ticket office and get a printout with minutes to spare. Fortunately the train was the wrong way round and I didn't have to walk the full length to get to the bike spaces. Grrrrrr.