You don't have to stir, but it does benefit from stirring. I find the Pax oven a bit messy to fill. I would not want to try dumping and crumbling if I were trying to be discreet, or filling it for that matter. If ever a device needed an accessory tool, it's the Pax.
Yup. Just filling is much more difficult than many - drop a pinch, press down, repeat couple times. Nothing hidden in filling it, and if there's the slightest breeze, - oh! - but stirring seems pretty required. I think the oven cover could have some blade or something that would roll with the top and in the process stir (or something like that thing that looks like an inhalor device which has a spring-like thing you turn to stir). Removing the oven lid when the thing is hot to stir is very difficult. But it seems to have to be packed, so you can't shake it and have to stir. But ... an absence of glass is not bad although at the cost of efficiency and flavor. Tough to fill, tough to stir, but easy to carry and use and it is small..
Differences I found in load amounts: Solo uses less, seems to me to last longer, better taste longer.
Putting a ruler to Pax and Solo - Pax mouthpiece not out but it is very short. NO GLASS!
very non-descript looking.
What I'm calling the Big Little Three :