About 6mos ago I bought the 0610i as a 2nd charger along with an Ice charger for doing 2 batts at once. I run them both with a ProPeak 20a PS and I've never come close to taxing it. Its a 13.8v about 275watts and was $59.95 new. The 0610i is a great charger, really happy with it.
But, now I seem to be getting more into lipos and wish I had bough the Duo for a lot of reasons, mainly because it would have been cheaper up front than adding a 2nd 0610i like I'm faced with now to let me network charge batts to run together as parallel pacs. Real important if you're into elect planes.
I guess my advice is to consider your future needs and see if your choice will take care of where you might be in 6months to a year as this side of teh hobby evolves.