Honestly I like them the same as my magic flight launch box and think that one has a easier learning curve.
And the magic flight launch box can be found much cheaper than the iolites and there is a knock off that works pretty much just as good for even way less, the dragon lite, as low as $20 brand new with one rechargeable battery.
In either the iolite, Wispr2 or the magic flight/dragon lite, a fine grind on you herbal mixture, tobacco or weed. The fine grind is needed to get the hot air evenly around all the material to effectively evaporate all the active constituents like THC.
I do not like the Dragonlite warranty or dealing with the company, I guess you get what you pay for. I recommended getting the Magic Flight Launch Box for about $80, unless you can find the Dragonlite for $20 or less, it is only worth that much and I would consider it disposable and not deal with its warranty as it'll cost you almost that much in shipping to get it replaced, however, not only is the MFLB better quality, the warranty is much better and easier to have fulfilled.