I use the Adventurer (and before that, the Classic).
The "reach" of the UV rays are pretty far, say 8" or so from the lamp. So simple swirling will kill everything from the tip of the lamp to the surface of the water, within most containers. Mating and tilting of the pen + bottle is overkill, IMO. Careful filling can avoid contamination of the threads, although the no. of nasties caught there are minimal.
My favorite container is a 1L Nalgene Cantene which, although not the lightest option, can fold up easily, and accepts the SteriPen pre-filter if you want. Another advantage of the Cantene is that it can carry that last liter of treated water, providing dual use. I'm pretty sure the folks at Hydro-Photon have given the Cantenes their blessing for safety. Note that the more useful (volume) 1.5 L Cantene is too deep for use with the Adventurer unless you tie a lanyard to it.
I use blue Tenergy rechargeables, the 900 ma ones IIRC. They provide ~26 liters at home (best-case scenario), and have treated ~10-12 liters in the field in temps. ranging from ~40F to 70F (not the most challenging field test), with power to spare. I don't carry spare batteries for short trips, and haven't noticed dramatic parasitic drain; maybe I have a newer version.
Re: Journey vs. Adventurer... The lamps are all the same size, so it's a matter of weight and display. Journey is a bit heavier (1 oz.?) but has the LCD readout (clock and smiley face), while the Adventurer has the somewhat cryptic LED (slow flash, fast flash, red, green, what?). The Opti has an LED light (for treating water in caves?) Check the PDF docs on their website and see which interface you like better. Mostly, it's a matter of practice... The Journey will mate with the bottle, but I think that's overkill.