I needed rechargeable batteries for the heated innersoles I bought this past winter, so I bought eneloops and their proprietary charger, which have garnered unanimous excellent reviews. (Edit: I also use them in my pocket electric shaver.)
My experience is that they don't compare to basic copper-top Duracells in either strength of initial charge/recharge or longevity.
They are a hell of a lot less costly to run, though.
