Nataly, I attend a reformer pilates class. It is very different from a mat class because you have a machine to offer the counterweight instead of your own body. You can work harder. But you can also be very sore the next day.
I like the class ok. It's at a convenient time and I like using the reformer. But the instructor likes to use a lot of variety in her class. I'd rather just do the same routine every time adding on at the end as we get more experienced. I like to get in the groove and really relax as I do it but I have to focus too much on what I'm doing. And since I've taken mat classes before there are some things, like the 100, that just seem silly on the reformer. I usually just move to the floor for that. Reformer classes are also more expensive than mat classes. But my local Y has a beautiful reformer studio with 10 machines.
all that said, I'm seeing some results. I don't have the neck pain I used to. So even if I'm all frustrated, I tell myself that it's cheaper than a physical therapy copay.