I have a pair of Newtons. I put speed laces in them and have only used them for sprint triathlons and short brick runs. Longest run in them is maybe 4 miles?

I pronate, so I put my Sole Comfort inserts in them for more arch support. I like them ok, but I have been afraid to try a long run in them. I use Brooks Trance for my long runs. They are comfortable, and so light! That is why I like them for brick runs. Especially when I am doing the run off a long bike. A really heavy shoe then is hard to take!

I do suggest easing into them. I have some friends that have used them for Ironman, but I don't think I will. I did really feel good in them during the tri's I did last summer, but again may be due to their light weight. I am usually in much heavier shoes.

Will be interested to hear your experience w/them!
Laura