Dudevato,
Subject I have studied. Designed a AA battery cycle tester a while back.
My camera says alkaline only.
I use NiMH with good results. (better life than expensive alkaline)
I bough a batch of cheap NiMH (2500mah), first use were amazing. Second less amazing, by 4-5 uses, on par with life of alkaline, continued to go down hill from there. Stopped using by 10 cycles. The good news, the batteries cost less than a good alkaline, not too disappointed.
A good NiMH battery cost 3-4 times as much, may last longer. Older (energizer) 2000mah worked in the camera on par with alkaline, had way more than 10 cycles.
Improper charging can kill even a good NiMH.
Make sure you have a good charger.
Over charging will dramatically reduce the life of a NiMH battery.
If the charger makes the battery hot for a long time stop using it. Last half hour is the longest the battery should be hot. Longer starts destroying the battery.(search Google on it)
Be careful on your interpretation of HOT. Few deg over room temperature is normal for charging. If difficult to hold then too HOT. My intelligent charger (PowerEX) will sometimes make the battery very hot. Other times barely warn. No rime or reason. Stand by hold, usually battery is room temperature, other times rather warm.
Recently bought some Juice AA 2000mah batteries, use in a flashlight that gets left on frequently. Works fine in this application, got them for 41 cents each. Not tested in anything else.
Have fun,
Scott.