We can fit two of our deep baking trays side by side on the top shelf (37x34cm) and got all the party canapes done in one shot. The sliding tray is surprisingly strong, it took our 7.5Kg turkey easily for basting and turning. We mounted ours at worktop height which makes transfers of heavy roast to the worktop really easily.
There's a couple of things we hadn't picked up on in other reviews. The oven external cooling fan pushes the air out of a slim grille at the front. It catches you in the eyes at worktop height. Shame. A hardware switch somewhere to reverse the fan so it draws in from the front and exits via the back would fix this. That fan is also quite loud, made worse by the grille being so slim.
Having multiple options accessible only using two knobs/buttons is never going to be intuitive to a new user, however, after a few meals the most common requirements are learnt quite easily. The minute timer is just that, a minute timer. This means the timer isn't totally useful as the main kitchen timer. We do use half minutes quite regularly so still have to use our phones or iPad (boiled eggs, steamed veg).