Look a the whole ballgame, not just one at-bat:
As you stated above, rubber and felt with studs are close in traction in the water, depending on conditions.
But Rubber:
Provides better traction on the bank (even if you don't hike in very far...ever walk a muddy or leaf covered trail up and down the bank?)
If you do most of your fishing from the bank, okay fine. I do most of mine from in the water. It's worth it to me to choose felt and choose a more reasonable route to the water than to trade the (imho) best traction while wading for incrementally better footing for the 8-10 steps from the trail to the water and back.
Provides better traction in icy or snowy conditions as well as just with freezing temps. No need to buy a second pair for winter.
No argument. Felt is ridiculous in the snow. That said, when the snow's flying if I'm in the water, I'm holding a shotgun, not a fly rod, and for that, 5mm bootfoot neos are the order of the day.
Has no regulations banning them when you travel. No need to buy a second pair for traveling.
I suppose if you travel a lot, that might be a valid consideration, or if you live very close to a state line...but if you don't travel much, I can't see the justification in making a purchase decision based on less than 5% of intended use...and if you're traveling a lot, an extra set of boots is likely something you can budget for.
Is non porous and less likely to pick up and transfer invasive creatures than a porous sole.
Dries quicker than a porous sole that holds moisture which may allow aquatic creatures to live longer.
That's a whole other can of worms, but suffice to say, I couldn't care less. I'm not convinced that felt is the bad guy it's made out to be, and the insides and uppers of most boots retain just as much water as the soles, so if you're drying the boot out completely, inside and out, felt isn't taking that much longer, and if you're considering the outside only, the rubber sole is actually more likely to be infectious, as the outside will appear dry long before the padding inside.
[quoteGrand slam!!!.... ymmv[/quote]
YMMV indeed. There's definitely differences, but just like rod action, it's very subjective and dependent on the requirements and intended use of the eventual owner. Also like rods, the best way to find out is to try them out, but that's a luxury we rarely get without doing it the hard way.
Luckily with my Korkers I got to try them side by side in identical conditions...I was really looking forward to liking the sticky rubber & studs, but in my experience, it wasn't even close to the same traction, so different, in fact, that I struggle to believe anyone who says they get better traction with rubber, thinking that the rather have other reasons in mind, like the ones you've mentioned.