Can't vote because you don't have my setup, but I like the 4/5A GP2000 for high-current in a relatively small size light (2.3D). That's a runtime somewhere close to 35 minutes. My MagCharger85 uses 8 1/2D high-current 4Ah cells (9 cells tends to blow bulbs). That's a hour's runtime. Not bad, plus its easy to charge, but a little big.
I built a Mag 3C with 3 AW C li-ions that I liked a lot, but the cells had to be charged out of the light, with a balancing charger being best. I like NiMH cells best because they can be charged in series in the light without the need for balancing.
The things that make Mag85s come alive are:
Regulation (soft start being next best)
High-current cells with at least 2 Ah (half hour) capacity
In-light charging system
High quality small-hole reflector
Low-resistance fixes
Dark nights