Pros: Saves $$$, reduces batteries going to the landfill.
Cons: ...could be a little less $$$.
Our family standardized on the Energizer rechargeables for a couple reasons. 1) Easily found in AA, AAA, C, D, and 9v versions. 2) Since they make all the standard sizes (other companies typically do not) and have a whole line of chargers available - it shows us that they are committed to their rechargeable line. Many other companies just have AA available...
Price listed is for a pack of (4) AAA batteries.
I have been using energizer rechargeable batteries for some time now (a few years) - the 900mAh previous "model" were OK - still have a number of them. The newer 850mAh version seems to hold a charge longer, and last longer when in use. Not sure why it is rated less "mAh", but no problem - likely just a small trade-off for better internal technology. They definately perform better for our use than the 900mAh version and no problems yet experienced with them.
I charge them - and the other sizes like AA and C - with the Energizer Family Charger. Has a digital read-out of the progress and if "Done".