I also got a 1000mAh Twist today and so far I love the thing. I've noticed that if I set it to 4.8 I get a burnt taste. I need to get some carto's with a higher resistance. I've found the sweet spot for most of my liquids to be around 4.0 +/-
If you are looking into a ego battery I would suggest picking one of those up over the standard ego's. They are priced very reasonably and you get the variable voltage option.
Also it would be cool if they could add a passthrough somehow if they release a next generation. A VV passthrough would be something I wouldn't think twice about buying. Not sure if a VV passthrough is possible
Be pretty tough to do a PT considering the Pot is on the end of the Batt to adjust the voltage, but would be cool if they could do it, I just dont see how unless they moved the pot up to the top under the connector maybe.