Well, I got too twitchy about it and went to see the M135i in the flesh...
Didn't drive it yet but just from a quick sit in with the engine on:
1) Seats are great (not the leather, just alacantra (sp?)). Possibly too narrow for the larger gentleman though. Definitely narrower than my Mk7.5 GTD. Seemed comfy and supportive enough but harder than my GTD seats.
2) Cabin is really nicely done, very classy. Only niggle - the central airvent opening wheel thingy is bright silver metal and looks right out of place. Looks like chav jewelry.
3) HUD is bloody brilliant!
4) Displays and MIB unit look really nice - very clear and stylish. Niggles are that the central panel and the dash panel don't actually align - OCD time! From watching the sales guy play with the system, the menus are a little clunky though but maybe he knew as much as I did. Major issue for me is that BMW don't support Android Auto. You can't even pay for it. Life without Waze might be a pain. If you are an Apple (freak) it does have wireless carplay and wireless charging.
5) ACC is not standard. Not sure if its in the Comfort pack, its not in the Tech pack which this car had. I use ACC a lot.
6) In real life the car looks pretty good exterior wise. Quite Golf-like lol. Salesman upset when i said that!
7) Engine made a lovely burble when i fired her up.

Looking at the long term fuel economy of the demo vehicles, its averaging 26mpg. That's not great. I guess I should have expected it to be R like given that its 300bhp 2l and 4wd. Not sure I can live with 26mpg.
9) The boot looked as big as my Golf GTD (the figures are identical but pure litres vs actual boot shape can tell a different story)
Anyway, a test drive is booked.
Oh and while I was there, I saw the 118 too - its quite nice but the demo one in the showroom had orange leather seats.... which were looking ever so tired already. How long has that car had people getting in and out of it? That's terrible! The leather was saggy, the drivers door edge squashed down and some stains already. I'll try and see if I can find out the mileage but it can't be high...