If the PT was a little less expensive, it would be nice, since you can get 2 batteries for almost the same price, it isn't as good of a deal IMO. I mean, I am paying for the same unit, with a USB port on it, and a cheap USB cable, not exactly worth the up in pricing, but I did buy one, and I have other ego/rivas laying around, it is a neat way to always have a charged battery on hand, but since there is a life span on the battery, it doesn't seem much better to me. The only real difference is the fact you can use it while it is charging I suppose. Everyone wants something different out of their PV, so it's hard to say whether it is better for your needs or not. If you think it's better to get 2 batteries instead of one, get a kit. Either way, you have a consumable product that will eventually fail. 900mah will give you longer times between charges, but still has the same over all life span... just my 2cents...