I recommend either getting studs or just get felts and put in sheet metal screws. With the metal, the felt soles will last much longer (3 times as long at least).
A friend of mine says instead of felt, get shoes with that rubbery type sole, but with spikes. (He has the Simms). He says those rubbery type soles, Aquastealth I think, are slippery, but with the spikes you have good grip, and they last forever.
If you do a lot of walking on backcountry streams, regular felt soles without spikes don't last long at all. A season or two is about all.
If you're getting a good discount, go for the Simms Guide boots with the Aquastealth type soles, with spikes.