This GE range was a replacement for a Jenn-Air CVE1400/4180/4210/4270 series downdraft for which we could no longer easily get parts. If you are considering the same swap, then you'll probably find challenges lining up with the existing duct-work. The required opening is the countertop is almost identical, the GE requiring 5/8" less distance from front to back and just 1/16" less side to side. So it slips into the old aperture easily, and with sufficient overlap that there are no gaps. The outlet to the ducting is 7/8" more to the right and 1-7/16" further to the back than the Jenn-air, which isn’t much but enough to cause problems because the fan box (plenum) on the GE is considerably longer, at a distance of 6-3/8" lower than the Jenn-Air. Added to that is the need for a 10" x 3-1/4" rectangular to 6" round transition adapter, which is longer than the required Jenn-Air 5" round to 6" round transition, all in all coming almost to the bottom of a standard cabinet, which leaves very little room to crank over toward the old duct-work.
For me, the ducting was by far the most difficult and time consuming part of the install. When I later noted that the Amazon price for installation is $180, I thought that it was a great deal. Then looking at, "What's included with service" there is no mention of the duct-work. If you choose this option I advise checking with the installer.
When installing the GE range you alternate between thinking, "this was thoughtful design" to, "why didn’t they just do this to make it easier". For example, when fitting the fan box you see an apparently useless hole in the top of the range cavity but you soon realize that it happens to line up with a dimple in the fan box that together mean that the weight of the box is supported while you install the fixing screws; good thinking. On the other hand, the first operation is placement of an adhesive foam gasket seal around the periphery of the underside of the glass top, and while doing this you wonder why the customer has to fit this, and not GE. The electrical box is attached with 2-screws, one at the back that is really hard to get to and one at the front for which your screwdriver will be difficult to access should your cabinet have a central divider. There seems no good reason why this box could not have been retained by screws to the sides. The instructions say that the electrical box takes a ¾" conduit, but mine had a hole for a 1" conduit, which could be a nuisance if you're not prepared.
The GE range itself looks very sleek on the counter and so far has operated just as advertised. There is, however, room for improvement. There is only a single light to indicate that a heated element is on, but to see which requires checking the position of each control, which on our black control knob on black surface range, isn’t that easy. There are, however, "Hot Surface Indicator Lights", one for each side that remain on after switch-off as long as the glass on that side remains hot. The indicator to show if the front left control is on front-burner only, or front-burner and bridge, is a minute rectangle which is either filled or open, and is very hard to see.
At the time of writing we are scared to death of spilling anything just in case it spoils the looks forever. I think that this range's surface is going to need a lot more cleaning than that of its predecessor, just like our granite countertops and stainless steel fridge. Progress? Form over function?