Vapour path isolated from the electronics, materials like glass and titanium, convection heating with a max temp of at least 430-440 f, single degree temperature control but 2-3 preset in addition would be nice, removable battery non proprietary, clouds, water option, on demand but a additional session mode is acceptable, efficiency, fast extraction, adjustable bowl size between .05-.15, should be so easy to load/unload that no one is even interested in capsules, size no bigger than a crafty, simple with no specific technique for good results, and finally price which should be competitive but I don't really have to much problem paying a premium if the device has the performance and features I want I'm a believer in if you build it right they will come.