basically something that wont reek if I keep it in my pocket for the day
Some are worse than others for smell, but whether 'in use' or just sitting cold, there's no guarantee against smell. And even if you can't smell it, that doesn't mean that others won't. A cig smoker doesn't usually think he walks around smelling like stale tobacco smoke, but non smokers are likely to call him 'stinky'.
As for the iolite, I've used 'em a lot, and IMO the smell factor is fairly low. The DaVinci is much more to my liking for portable use, but for some reason the smell factor seems higher.
For sneaking quick hits and carrying around all day in a pocket, I'd give the Magic Flight box a high rating. For fast heat up, a quick mini/micro hit, and back in the pocket, it's hard to beat. You'll also get 'effective hits' that won't produce a lot of smelly vapor. Big hits from a portable can be counter productive if stealth is your goal. The iolite, like the DV, needs to heat up, and even though 90 sec. or so isn't long, the MF is much faster for heat up and cool down. The iolite, DV, and many other portables are also still gonna be at vaping temp for the time it takes to get several hits, no matter how soon you turn it off. As with any vape, keep it clean if you want to keep odor down. Stale mj odor can be as bad as fresh.