that 19 looks awesome - i saw that in another thread. THe magnetic switch is really a nice feature (gg inspired) and magnets don't lose their strength so the switch spring will not degrade over time since there is no switch spring.
A lot of these devices coming out of the China Cig district are getting better and better - and they are mass producing them like crazy. Again, the quality is no where near as good as the luxury mods, so you're truly getting what you pay for wherever it's a 30$ device or a 300$ device. functionality wise though, the ZMAX Telescope and even those Sigelei Mech Mods, they do what their main job is, which is to perform - at first they function ok, but once modded or given some slight love and care, they can perform great with minimal voltage drop.
now back to the ZMax V3 telescope - great build - great metal quality, and the i love that the 490/500's can fit in 350 mode, so the device isn't that big at all really - a little wider than the zmax v2 since it has to hold the telescope tube - but still acceptable.