Thank you for your replies. Actually, I've been considering an fscan pca rather than an fscan2. I didn't realize at first that they are different. My major worry is whether or not it will be strong enough to make a difference to the outcome of my experiments. It's important to choose the first machine rightly because I won't be able to afford a second machine. It will be a lot of fun to learn to use it (if I buy it). I need something with both diagnostic and treating capabilities, and the FScan is the only machine I've read about that does both. But I keep wondering if it's strong enough.