I've waded with felt soled wading boots for more than two decades and have worn rubber/stud soled boots almost exclusively for the past three seasons (I still wear my felts once in awhile in some warmwater rivers). I fish alot, and I fish in all types of streams and rivers.
Putting the regulations aside, when my boots need to be replaced, I will choose to buy another pair of rubber/stud boots to replace the ones I now wear. I can wade safely in just about all types of stream/river bed with rubber/studs, and I find them vastly superior to felt soles when walking on or climbing up or down on the bank, in mud, in wet leaves, in snow or ice (I fish a lot in the winter). Overall, I find them superior to felt. YMMV, as always.