We've been going to a pilates class, and wow, is it hard. I thought the stroller class brought the pain, but that was nothing compared to pilates! If the two classes got into a fight, Pilates would definitely come out ahead...probably banged up pretty bad...but victorious, nonetheless.
First of all, pilates is about 10 minutes longer. Ten minutes may not sound like much, but trust me, when you're on your hundredth hip circle and the burn is making your eyes cross, those ten minutes seem like an eternity. Because there's walking involved, the stroller class also allows for more rest. I think in the 60 minutes spent doing pilates, there was maybe 2 minutes of rest.
The major problem with starting a new class has been going back to the bottom rung of the skill ladder. It's very humbling to watch others do something with ease while you're huffing and puffing. Not to mention having a 60 year old instructor who is kicking your tail (she happens to be very strong!)
I loved the stroller class, and would still go if I could, but pilates has been a great substitute. We'll see if it pays off.