So, at first, these batteries were great. At a fraction of the cost, they lasted longer than my OEM battery. After 5 months or so of use, they started not getting charged to 100% (according to the battery info menu in the camera). I was still able to get a good amount of use from each charge though so I didn't really pay it much notice. A few weeks after that, charging only got up to 73%-82%. Now, at 11 months, I am used to it only saying 73% after a charge. However, now when I use it, it goes from 73% to 40% normally, then suddenly drops to 0% or dead.
I was out shooting video on my 5D3 for a commercial and it died after 5 minutes. I had just charged all my batteries (these 2 wasabi ones and my OEM canon one) earlier that afternoon. I took maybe 15 stills with it, then we started using the camera for video recording. After 5 minutes, the camera just started shutting itself off. After a little troubleshooting, I noticed the dead battery light flashing. I didn't understand how that could be as this was a newly recharged battery. So, I pulled it out and used the Canon battery and it lasted perfectly fine for the next 3 hours. A few days later I recharged the wasabi battery and played around with it while sitting at my desk and was able to recreate the issue. I tried completely draining the battery as far as I can before recharging it several times. Hasn't improved. I think I'm giving up on these batteries.
Apparently they don't sell battery reconditioners for lp-e6 batteries so I can't try it on them to see if that would help.
It's too bad. These seemed like such wonderful batteries for the first 9 or so months. I have even recommended them to several people. Guess I have to bite my tongue now. I still don't believe in paying the insane prices for OEM batteries. For the amount of use I got out of it for the price I paid, it might be okay. But, I'll probably try a different brand next time first.
Update June 4, 2013 I started using the Wasabi charger to charge the Wasabi batteries exclusively and it seems to have helped a little. Both batteries are now back to working they way they did as I described above at the 11 month point. In comparison to the OEM battery, they now last 2/3rd's as long. Not so great considering my OEM is rated for 1800 mAh and these Wasabi ones are rated at 2600 mAh...
Something else to note, the wasabi batteries are specified as 7.2v, where as other batteries (ie STK) are 7.4v. So maybe as the battery is used and its voltage slowly drops, it goes below the minimum voltage threshold of the 5D3 even though there is still a good amount of power left sooner than the other batteries. *shrug* I did initially buy the Wasabi because it was 7.2v just like the Canon one though.
The most annoying thing about using these batteries in my 5D3 is the fact that once the battery charge indicator drops below 50%, the cameras FPS drops from 6 down to 3 or so. So every charge I get full performance from 73%-50%, then reduced performance from 49%-0%.