I was using FIN, but our local stores stop selling the vapes. They were the nearest to a perfect cigarette as I had found. I began using the Mark 10 XL and it ran a close second, but I have noticed lately that the $7.99 two-pack cartridges do not last as long. I had not increased my intake, more so, I feel that in an attempt to cash in on the popularity, they have decreased the amount of fluid in the vape cartridge so you will be purchasing more. Any others noticed this?