I understand this thread is a couple years old but we just replaced our 120 Advantium 27" wall oven and thought I would share our experiences.
We purchased our original unit about the same time this thread had started but if I remember correctly, I don't believe it went into service until May.
We use our Advantium almost every day. Not really in microwave or speed cook but as a warming, proofing and convection oven. It especially comes in handy during the Holidays and gives us a third option in addition to the Profile double convection. We had pretty good luck, over-all, with ours. The only major issue was a bad magneto but that is a one in a million issue and can happen to any manufacturer. The most pesky issue was the light bulb but we had an extended service agreement with the dealer we purchased it from and it was replaced without questions. I vaguely remember needing a new convection fan but that was right at the time many GE ovens were experiencing that problem.
The first oven served us faithfully for almost 8 years. Granted I would have liked to get a couple additional years, given the cost, but we really did use it allot! Anyhow, I'm guessing one of the control modules or maybe the board failed because I set some pizza in to hold while I picked the DD up from school, and when I came home the oven was actually over heating for the desired setting.
Yes, there is an inherent risk in using anything when you are not home and this potentially could have been a problem because any cooking tool can malfunction and the reason why but I also knew I would be gone long enough to cause a catastrophe. Anyhow, when I hit off, the oven continued to heat with the display registering coll down mode. That's when I knew it had to be replaced. Even though the repair could have been less than a new model, it was 8 years old and we are in the middle of replacing all the painted face appliances with Stainless. For the repair to be cost effective, I needed to perform the work and I just don't know enough about them for that to happen.
We did purchase the new model and so far, it looks like GE has done some major improvement's. Although we never had an issue, the handle has been redesigned and is much more durable than even the one we had. They increased the gap between the top edge of the door and control panel to allow for greater ventilation so this should reduce any heat issues people may have had with the control board. We've had it installed now for a week and seems to be working just great! Mostly used as a warming or holding oven this last week, we haven't used the convection oven yet but that may get changed today. Tuna noodle casserole is possibly on the menu and that oven works perfect for smaller casseroles. I had thought about upgrading to the 240v model but it wasn't worth the hassle of running new electric to that portion of the kitchen....again....and we would have needed to replace the cabinet...also again...... since the 240 is the 30" model.
I can't speak for the over the range model and with all the heat that can be generated on a stove-top that might be the source of some of the issues but......if you find yourselves needing to replace an existing Advantium wall oven or have never replaced the original or have a gaping hole in a cabinet from where one was removed, it might be worth a shot to try the new model.