Great fun. Possibly the only time you’ll get to ride with 5,000 other folk. The locals all come out and support it and it’s great to be cheered along as you go. The segment round Loch Rannoch can be a bit exposed and into an awful headwind on the way out but it’s otherwise a nice route. There are a couple of little “stinger” climbs in the last bit from Logierait though and make sure you are in a low gear when you turn up and left, away from the hotel.
I’ve done it twice. The first was the “Etack Caledonia” event and I got severely chilled at the top of the Schiehallion climb as they waited to make sure it was safe to continue. The following year I managed round in a respectable 4h13m.
It is, however, a bit expensive and be aware that none of your entry fee is going to charity – it all goes to the event organisers.
If there’s an STW “recce” ride, I’d be well up for coming along.