Since the GLE550E, hybrid, is basically identical to the GLE400, with the addition of the electric, and I believe the base price of the AMD GLE$# is about $1,000 more, PLUS then I got a $4,085 federal rebate, it ends up being $5,085 or so LESS, and .3 seconds quicker to 60, (5.3 vs. 5.6 seconds) plus much better mileage, I think this is the way to go, unless you want a lot more horsepower that the 550e, which has a combo hp rating of 436. (the base price might be different, but includes I believe some options in the price.) Either way I am loving this hybrid.