While I don't have one personally, I've heard a few people talk about buyer's remorse with them.
According to said people, when you watch the demos (and I'll agree because I've seen a few of them) it's billed as this great time saver and way to healthier eating. For me, while the time saver part might be true, it's only "healthier" if you put healthy stuff in it. At one demo I saw, they had a small print out with a couple recipes on it. I don't think many people would consider cream based soup and milkshakes healthy. Now I don't know who made these print outs but it would seem watching the demo that while the salesperson goes on and on about healthy eating, that the recipes being handed out would be healthy too. In the same vein, the biggest reason for regret seems to be that to truly use the machine to work in healthier foods, the owners find their grocery bills go sky high buying fruit and vegetables. That plus the cost of the machine just turns out to be too much. One person said their neighbors in an apartment building complained about the noise in the mornings, another said their own family complained about the noise.
So to me it seems like its only a good investment if it suits a situation you're already in. If you're not used to buying a lot of fresh produce and healthier items, you may find the cumulative cost to be overwhelming, or if you live somewhere where the noise would be too much it might not work out. All of the demos I've seen where in large "rooms" where the noise had lots of room to go, but in normal kitchen it's going to sound a lot louder.