I think I will try the front wheel first and see how it does.
My concern is that I will loose some contact area..
Sure, I will pick up some tire width but I will be loose some contact in the length depending on tire pressure...
Of course, going from a 21 to a 17 on the front is going to change the handling so I probably won't really know the real over all change unless I do the back as well... It's only money...