the only rcr123a i have used was tenergy and ultracell (lifepo4) and some unknown regulated li-ion 3v cell. the ultracell and regulated cells worked good for a couple months, but the tenergy lasted a year or more of consistent results.
these cells were all used in a prodigy v3.1 ecig, stacked. tenergys consistently lasted more than a full day, while the other cells regularly needed to to be changed out mid day.
im sure you are looking for 3.7v cells, so this may not be of any help.
I have a Yezl 880mAh 16340 which seems to be pretty good. Have also just ordered a Nitecore RCR123 650mAh after hearing a lot of positive comments about them.
I saw a nice review for Solarforce when I was looking for a better alternative to Nitecore. I'll get one sometime. I don't think there's there's much difference in the best 16340 cells, not that they're that great.
$3.50 each + $2 shipping. Using my Thunder AC680 hobby charger, their capacity is around 720 mAh at the industry standard .2C (used .2A) when discharged down to 3 volts from a full charge. They are the highest capacity 16340’s I could find and they are cheap. The only downside is that they are pretty wide, so they will not fit in all lights.
I am discharge testing my Trustfire 880 mAh 16340’s I got from Tmart as I type this. I will post the results in here once it is done.
Edit: 702 mAh on the Trustfire’s from Tmart. I am genuinely suprised by that. I thought they were going to be in the 500 mAh range…