I had a test ride on the Datum 10 the other day on a Madison demo bike.
They only had a medium so it felt a little small but it was lovely to ride. The Tiagra gears were really slick and the brakes were good. Went around the back streets behind the bike shop that was hosting the event and these were typical UK back streets, not big potholes but a lot of the surface was damaged. It just soaked that up. Bike felt light and fast even on the wider tyres.
Thing is though, why (aside from the colour) would anyone buy the 10? If you’ve £1800 to spend, you may as well stretch the budget and get the 20 because you get a lot more bike for that £300. It’s an odd price point to have 2 different models at. The 30 sits above them both and is obviously going to be above some budgets.
I went for a pre purchase fit. He suggested the Specialized carbon comp too (about £2.5k) and said the finishing kit was better on the Specialized.
I was weighing up whether to get the Datum 30, and even looked at the Specialized Roubaix which is £4k. At that point common sense kicked in. I figured a power meter would be more fun than electronic gears and the money I saved would buy me a bike in the future (or, if 105 gets di2 in a year or 2, the upgrade kit when it comes out)
In the end I ordered a Datum 20 with changed bars, stem and a power meter.