I've not tried he new one but the integrated switch solves one of the weak links of the old "one chance to get it wrong" design. That is, with the separate switch, put the battery in backwards (c'mon, it's not that hard) and no more switch.
I've replaced one ePower, the replacement of which is now a backup for my other 18650 devices. It's adequate as long as I pay attention to battery orientation.
Be aware that lightweight tubes do not perform as well as heavier tubes like a Chuck or a Silver Bullet but I can't figure out why.