Andel, that's exactly what I'm thinking, too. Being the difference between the 510 and 801. I, like most, started 510 and like I said, just recently started branching out. The vapor I'm getting off the 801 is just better.
The Darwin is also the first variable device I've used (ok, power reg.) So, that might explain the wow factor I'm seeing with them, too. It's a struggle to get wow'ed when charging and changing batteries, changing battery configurations for each juice to find the right combo... etc.
Does anyone else notice less frequent need to top off the carto when using an 801 vs a 510? I felt like I was basically dripping when using a 510 carto.
*Droid