Yes - was thinking I could be a bit exposed and messy if the weather was bad, similar to the Ridgeway but close to the sea and worse weather?
All in all I really enjoyed this route. 100% (imho) a 29er type of route, there was enough flowy XC to keep me happy I was on the Jones. I had 2.4 Rangers on which were a bit OTT but they're good XC tyres, fairly quick. I'm looking for something less buzzy on tarmac though, I'll either find them or wear the centres off these in time..
General waffle / for ref, if anyone's planning the ride -
I started in Goring which worked out really well - you get the least interesting section done at the start. TBH I thought the section between Reading and the M3 area wasn't great on the whole but I wasn't expecting much based on the guide that the more built up an area is the less I'll enjoy being there. To be fair the route does find it's way through it well with only a busy riverside path in Reading and some byways running next to noisy fast roads being a slight downer and don't get me wrong, there's some nice stuff in there.
As you get into Surrey the trails get good, often feels like you're riding along the garden fences of some millionaire stockbrokers but there's some great riding on sandy trails and loads of nice bivi spot options. Then the Surrey NDW trails change to the Chalk of the SDW and you're moving away from London (always A Good Thing). This is why for me the Goring start worked well, just as I was beginning to wonder if it was a route I'd enjoy it opens out and it's continually good riding. I was looking for the big open country of the western half and got plenty of that.
Really enjoyed the SDW-Salisbury plain-Ridgeway western 1/3 section and although I know the western half of the Ridgeway by heart it felt different ending along there, it was in context with the rest of the riding but 2 days of riding high added something to it. I rode home from Goring on tarmac as it was getting a bit late and my lights weren't up to off-road in the dark. I'd stopped near the end of the Salisbury plain section to meet a friend I'd not seen since he came back from living in BC, Canada (I wanted to know why on earth he came back

Riding time was a bit over 19hrs. Full route in 2 days without any riding in the dark, setting up a bivi at 7.30 both nights. To save a bit of time I skipped the Liddington castle section of the Ridgeway as there's a good straight line lower track/road to Fox Hill and the castle was crawling with Sunday aft visitors. That saves me about 30 mins based on past rides. I'd also gone off route poking about some singletracks I'd seen along the way and an added 10km or so to meet up for brunch so it probably balances out, ~20hrs for the loop. I say that as a guide not a marker time - that was my moving time and I spent plenty of time stopped eg Winchester was a good late lunch / early dinner spot but I missed the cathedral closing time by 10 mins, ah well.
I got a higher climbing total on the GPS than I did on the RWGPS file - 4500M+ vs 3500m. Still, not really a hilly route overall, 'rolling' in general and flat in places.
I reckon an early start Sat and Sun will get the route done in a weekend for those wanting a brisk but not too time-crunched ride assuming you're not on anything with skinny tyres, and 3-4 days makes it a nice trip. I'd really question the Cycling UK mention of a 'gravel route' and 35mm tyres and upwards, it's just XC. I'd have been beat to near-submission on my 650B gravel bike if it was loaded up vs having a great time on the 29er in comfort, but plenty of harder rides have been done on 35mm touring bikes.