They can cost slightly more than standard Ni-Mh rechargeables but generally have about double (1,000 or for Eneloops 2,100 cycles) the recharge cycles. So again you more than recoup your money especially compared to Alkalines.
Apart from that, they are similar to normal Ni-Mh characteristics running most of their cycle flat at 1.2V and down to 1V. I’ve started using rechargeables in my weather station, and I notice the device reports a low battery. This is because normal Alkalines start off at 1.5V and steadily drop over their usage period down to 0.8V. The Ni-MH start at a bit above 1.2V but drop to 1.2V and remain flat at 1.2V for ages until they start to actually get near the end of their cycle when they drop quickly to 1V. Most battery level indicators are set for Alkalanes so think the 1.2V is a "low battery". So if all goes well my weather station should just show :"low battery" for a couple of months.
So the Eneloop and Imedion batteries could also be better for use in very low drain devices such as remote controls – imagine that, one set of batteries for your remote – your remote will die before you ever need to buy another set of batteries!