I've had a few different microwaves under the counter. Currently, we have a Miele speed oven with the drop-down door and it's great. I like the door design and it's easy to use even down low. The handle probably sticks out a little bit past the countertop edge but I've never noticed it. Only negative is that it's a very expensive but it really can double as a second oven with excellent results. We also have a Wolf microwave drawer in another house and it drives me bonkers because it's slow to open compared to opening a door yourself. I want to grab it and yank it open and most guests can't figure it out. In our last house, I put a regular small cheap microwave under the counter in the island and without a doubt this was easiest and the best value, but in that kitchen I had room for two wall ovens so didn't need anything that could do double duty.

Personally, I don't think that microwaves even with convection are any substitute for a real oven unless they also have real electric burners and can operate as a regular oven without microwaves. To me, the food is never very good. I've tried all sorts of different models in search of a microwave that does double duty but without paying as much as the Miele cost. In the end none compared. The only other two that I thought might be ok are the more powerful Advantium and the Bertazzoni speed oven but if I remember correctly, neither can go under counter due to ventilation needs. The Miele can. My research is a couple of years old though and there might be new products available now. Good luck!

Is not an ideal position, but a miele speed oven would work okay just with how it's laid out. It's doesn't use a turn table and you can pull out the glass trays rather than the more awkward motion required with a regular MW placed under counter. It's an excellent no compromises (except size) full featured oven too. Expensive though. The bar will stick out a little more than standard pulls but I don't think it's a big deal unless you have door clearance issues with an adjacent beverage fridge or something like that.

If you didn't want to go all-in with a true built in, you could get something like Samsung MC12J8035CT convection micro which also has an available trim kit. We've been using it countertop going on two years. it's got good capacity but saves counter space because it has the fold down door rather than swing out. Might work for what you need if budget is important - around 6-700 with the trim kit (I didn't get). We use it mostly for micro and occasionally convection or combo. It's nowhere near as robust as a real oven, so it depends what you need. I have dual 30" convection ovens so this is a nice add on in our case.