eJohn,
I can only comment on my experience but the V2 seems to hit just slightly harder than V1 (I'm talking about full sliver contacts and hot spring vs. full rhodium and neg pole). When I'm saying "seems" I mean a simple inline cartometer and the ol' lung-o-meter.
Now, you can get V1 contacts to hit harder than a setup with full rhodium but you will have to: clean all (yes all) the threads on the mod with a brush (toothbrush, ect.) and a de-greaser (small drop of dish soap), clean all the contacts (including the switch contact rod), rinse all parts with ISO, denatured alcohol, vodka, ect. Apply conductive grease to all threads in ground path (I use NO OX ID a specia, cloud wizards turned me on to the stuff). Most importantly, stick at least on extra spring in the battery end cap (if you thread them together first you can seat 2 or 3 three instead of the recommended 1).
If you do all of that a setup with silver plated contacts will hit harder than the rhodium, for a good week (YMMV); but after a couple weeks (of heavy use) you'll hardly notice a difference. Then, (for me it was usually every 3 week) you will notice a drop, and it's time to clean again.
I'm talking about keeping a Poldi in tip top performance, that's what you're asking about; and that is what it takes to keep (any mod with silver contacts) in it's prime.
And that is the reason for the rhodium. I sold my V1 for a Cali. Does the Cali hit harder, yes. Considering on average or consistency, the rhodium (w/ neg pole) just slightly edges out the silver.