I know this is an old thread, but I recently looked in my bag and found a set of Sony Cycle Energy batteries that I'm sure were the same manufacturing as the first generation Sanyo Eneloop. They all have year and production codes, so those were made in 2008. I'm not sure when I put them in the bag that I found them, but I put them on a Panasonic charger and they were fully charged in less than an hour.
Just remember the current Eneloops are really made by Fujitsu after Panasonic had to sell off that battery division to avoid antitrust issues. But Panasonic owns the trademark and buys from Fujitsu. I'm not sure who else buys from Fujitsu, but the standard 2000 mAh AAs are really good. Unfortunately Costco doesn't have those any more. The Panasonic label started appearing around 2014. I still have quite a few batteries with the "14" date code and all are still running fine. I also have some older Sanyo labeled batteries. A few have failed, but only here and there. When they've failed I didn't see any liquid leakage like I've seen with alkaline. They might leak a little bit of dry dust out of the positive terminal.
I can't really say I would know much about how long they last as I no longer use them in any application where I would care. I typically use them in wireless mouse applications, and flashlights where I'll just charge them after a short use and rotate them in and out. I might have a 10 I use in single cell devices, a couple of pair for 2-AA flashlights, maybe 5 sets of 4 I use in 4-AA devices, a few AAA singles, and several 4-AAA applications (like a flashlight and a video remote control). I rather prefer these to using alkaline where I'll try to get as much out of them as possible rather than charge the batteries proactively.