Funny about the stems, when I got my 107, I couldn't get the stem in and asked Arizer why they didn't send the proper sized stems. It just took a couple of seconds of work to get it in. At this point after, weeks of use, my stems rotate freely, and can be slightly angled during a draw(which increases airflow), but there is a slight point of resistance inserting the stem and removing, almost a click lock sort of thing that keeps the stem somewhat secure in it's seat. Don't get me wrong, you won't be walking around your house with the Solo hanging out of your mouth by the stem, but the current state of my stem is an interesting combination of loose and secure that I'm very happy with it.
Your hesitancy and desire to get information for your informed purchase Vis is something we all go through here, you can find my initial hunts in these threads as well. I'm currently stalking the Da Vinci, Pax, and Puff It Stealth(although they're not winning me over), there was the Vaporblunt and the previous Stealthvape but they might be gone by now.
Something to consider, other than the earlier smell issues, I imagine there is very little negative feedback about Solo performance, and quite a bit less compared to it's competitors.
I wholeheartedly recommend you buy this vape, quick heat up, long battery life, and incomparable clouds for a portable IMO.
Good luck!