I hesitate to post but I'm really impressed with the Energizer rechargeables in my True 30mW. When I used absolutely fresh Alkaline (Duracell) batteries the power was about 38mW and then quickly dropped off to about 25mW over 5 minutes or so of use. After another 5-10 minutes of use, the power was down to 15-16mW. With freshly recharged E2 rechargeables, the power was initially 35mW dropping to 32mW after a couple of minutes and staying that way for some time. After 30 minutes or so of use, the power is only down to 28mW.
I haven't tried the E2 lithium yet but I'm pretty satisfied with the the E2 rechargeables. The price was right too... The local Meijer's had the two E2 rechargables packaged with a compact USB charger on sale for less than $10.00 just before Christmas.