I'm new to vaping but figured out rather quickly the tank would be ideal for my lifestyle, like on the go and gone long times. My first kit is the Riva 510 from LF. On their site under compatability it says the EGO tank and atty will work fair with the Riva. No where have I been able to find what "fair" means. I'd rather have the 750 mah batt than the 650. Can anyone please tell me what to expect if I put an EGO-T atty and tank on my Riva and what "fair" may mean. Normally a 750 batt lasts me all day but I did manage to vape one to its death once. Carrying another batt would be a lot simpler than all the carts and liquids. Thanx, Chuck