So, I finally got round to trying out the Interdeck coach on the X9/X10, and they're a bit of a mixed bag for me.

First of all, the stairs. They're steep! I didn't realise on the way up, but on the way down I thought I'd missed a step! It took about 10 minutes for all the old biddies to get down when I was waiting to board!

Comfort wise, it felt about on part to the new StreetDecks to me, although it did feel a bit more unsettled on the more 'normal' roads than I expected. On the motorway though it was very smooth. 
I'm not a big fan of the seats if I'm honest, the shape of them just felt weird, they're very sculptured, with the sides being quite a bit higher and firmer than the middle, which actually made it feel as though I was sitting on the toilet until I'd sunk into the seat!

They certainly feel like they've got plenty of power, and felt like they were actually limited on the A19.

Leg room seemed adequate, it still felt a little tight on the standard seats, but the seat behind the toilet had mountains of room, and a great view of the NSA screen.

Speaking of the NSA, it seems somewhat more limited than it used to be, it no longer gives estimated journey times which was one of the things I found great, especially as someone who doesn't really know the route. Although I did appreciate the fact it truly is an express service and don't have the constant "Next Stop" blasting in your ear!

The best seat is definitely the one directly above the driver, although I did nearly knock myself out trying to sit there due to the low ceiling! You get a brilliant view out of the window, and a 240V socket! Plus the ride felt a lot smoother, maybe because you're not directly over the axel like you are sitting near the toilet.