Jim
I replaced it myself in Sept. of 2011 with a GE model JVM 1790 which has a turn table and larger capacity, and BTW the only model available at the time. One problem I had was the hinge on the door is not the same and without a filler in the back to make it stand proud in the front the door would hit the cabinet. This is only true on the models with the kitchen in the slide like ours. It wasn't real hard and didn't affect function at all. I did have to rework the two screws that go down inside the top to hold it up, but it became obvious from the get go. If you do this be careful when you remove the old one, it will hinge down and break the mirrors on the backsplash.
DW likes the new one a lot better. Besides the turntable and the ability to put two dinner plates in for warming, she says the convection mode is a lot better for baking.
Here are some pictures of the install and the filler.
https://skydrive.live.com/?cid=ae67f...057%211736&v=3
And also some pictures of the new backsplash.
https://skydrive.live.com/?cid=ae67f...057%211715&v=3
Dick