Has anyone on MFP had any success with weight loss using Eliptical?

I don't think there is a real difference between one or the other, but I prefer the elliptical.
That said, I am now starting to see the changes I want by adding weight lifting to my workouts.

Elliptical changed my life by making it convenient to get exercise no matter what. It's much more comfortable for my body and is better for posture/body mechanics than treadmill I think. Also I can do elliptical even when I am dealing with back or neck problems which has really helped with staying on track.

So I highly recommend it but of course it only works if you use it, otherwise it's a crazy expensive coat rack

Either one is fine, will burn calories, and build yoyr cardiovascular fitness, but do what you like best. If you enjoy the exercise you are doing, you'll be more likely to stick with it. I personally prefer running outside, but I do add 1 day of non running cardio each week, alternating between bike, elliptical, and stair climber.

I love it all. I alternate between the two. It's a great workout! Love the resistance options. You can squat down a bit and feel it more in the rear too.

I find a good elliptical easier on my knees than a treadmill. so I prefer that over the elliptical. I still try to mix it up if I see plateaus in my progress. At some point your body adapts to the excersises and you see less results unless you can mix it up.

I prefer the ARC Trainer because not only is easier on my knees (OA in one and presently recovering from TKA in the other so not doing much cardio), but it also allows me to hit different targets in the lower extremities by changing to the different programs. The treadmill is BAD on my knees, and the elliptical has a stride that is too long for my short legs. The ARC is perfect for me.
OP, do what fits your needs and your body better; the best exercise is the one that you do with pleasure which in turn will bring you better results. But for losing weight you need to eat less and move more.