Meryl, I have an AeroGarden I got as a gift last Christmas...
First off, I have to qualify my opinion by saying that I am the "death angel of gardening". Give me any kind of living plant, including air fern, and I can kill it dead, dead, dead! in a matter of days/weeks.
Now that being said, I can give you my experience with the Aerogarden. I've had mine a little over a year and I must say for me, it has worked pretty well. I am currently between "gardens" as I have just ordered the hot pepper seeds and am waiting for them to arrive. So far, I have only done the mixed herb gardens.
Here are my pros and cons:
It is easy to set and use, although you need a bit of room for it as it is has to have room to adjust the light vertically as the plants grow. (So it wouldn't fit under a cabinet on the countertop except in the earliest growing stage). The kits come with the nutrient tablets and there are alert lights on the garden to let you know when to add water and nutrients.
The herbs all grew rather well, with the exception of the chives which seem to die out much quicker than the rest of the herbs. The garden was not always "picture perfect", but the plants were all full and healthy. Mine actually did look pretty close to the picture on the box when it got to maturity.
I actually had trouble using up some of the herbs as they grew so fast I was having to "harvest" them more often than I need them to cook with. (Otherwise they will grow too close to the light source and scorch).
The garden will last 3-6 months depending on how often you harvest, etc. I had good luck with the staying power of the 2 I've done thus far.
I would have liked to have had more of some of the herbs in place of others (like more basil instead of dill, but that is jsut a personal preference). You really need to look at the kits you buy to decide on which mix is best for you. They now offer a master gardener kit which allows you to customize your own garden. I may try that after the peppers.
Overall, for someone who can't grow anything, it has worked pretty well. Would I recommend it to you? It depends. I'm sure if you have any skill at gardening, you could do the same for much less money and probably would not be happy with the aerogarden due to some of the items I mentioned above. But for someone like me, who doesn't have the time nor inclination to maintain traditional plants, the aerogarden is a relatively easy way to grow things with minimal attention.
Hope this info helps with your decision. PM me if you have any questions.