Well, we've been using the maha rechargeables for about 6 months now, and overall, we've been pleased...
We can do 3 services plus a walk through on 1 charge, and we've only had 1 failure (probably because of a bad charge). I'd like to say that wasn't acceptable, but we probably had a battery problem once every six months with regular ones anyway, so that's not a big deal.
With the stuff that's not as high a draw (some wireless guitar packs, active pickups, etc) we can get a few weeks out of them before they fade (much less than the standard batteries) but we're not burning money so it's not a big deal.
But the one thing that came up (and it's not really a problem since we get what we need from the batteries every week) is that on our handhelds, they don't show a full 3 bars even when fully charged.
So, overall, they've worked out pretty good. I'm glad we switched, we haven't made up the difference in price yet, but we will in about 6 more months. We will still buy a few regular batteries (so we don't have to trade so quick in pickups and the like) but only about 10% of what we used to.
Overall, I'm comfortable recommending the maha stuff as long as it stays on a charger until you need them.
My 2 cents, anyway...
JF
