I purchased this wall oven specifically because I knew it would be a tight squeeze to fit any oven into my old cutout. Since my old oven (1980s vintage) was a GE, this model was slightly narrower than Kitchen Aid's 27", and GE has their "perfect fit guarantee", I decided  to try it. And it just barely slid into my space - hooray! 
The oven itself takes a long time to warm up (I think the older ones just heat up a lot faster), but does have some nice digital features. It was super expensive for what you get - doesn't seem like anything special to me, but does get the job done.