We would rate the appliance lift as a "nice to have" item. This model is made by Rev-a-Shelf, and was purchased through Rockler for $100.
It has really been convenient for my DW, who cooks from scratch most of the time. She lifts it up, uses it, and drops it down. The pull-out shelf below holds the mixer and food processor attachments.
The shelf is 18 inches wide (cabinet opening is 22"), so it holds two applicances - a Kitchenaid mixer and food processor. It's not too heavy for my DW to lift up and down. Note that it is also covered with 1/2" granite to match the counter.
If you install one of these, make sure to put an outlet in the back of the cabinet - it's well worth the effort. The cords lay behind the shelf as you raise it, and simply stay out of the way.
Here is a shot of the lift in the cabinet. I would have made the cabinet shallower if I had to do it over again. I wanted to keep the cabinet to a minimum depth so the back side of it could be used effectively. The instructions indicated you need 23", so that's what I made it to. In reality, I could have gotten away with 18" deep and saved 5 inches. This would have allowed us to put another stool on the backside, instead we put a bottle rack. This is not a terrible result though, since we like the bottle rack. There is also room above the applicances for a cutting board slot, but we haven't put that in yet.
In review, it was worth the cost and effort to install it.
