I have been looking for a long time for good 'studio' aerobic shoes that fit and were constructed of manmade materials (I'm vegetarian).  Ryka used to make some back in the nineties.  (Yes, I have been doing that kind of aerobics since the eighties.)  Finally I saw these Assist XT 2 and was happily surprised that they fit the bill.  They have forefoot cushioning, plenty of toe room, very flexible, and have support for side to side movement.  I don't have to use running shoes where all the cushioning is in the heel, and I don't have to use "crosstrainers" which tend to be too stiff. Thank you Ryka.