Great thread!
I have a Soltek easel (I had about 2 hours one day when I was feeling flush and decided to spring for it.) I like it a lot, although I am still trying to figure out the allen wrench adjustments. I am not a plein-aire painter, but I think it would be a good choice. It seems a bit too bulky for me if I had to fly, though.
For flying, I got the Winsor-Newton easel; it fits in my checked luggage - in the carry case, the length is 27". The drawback to this easel is that the tray isn't really high enough, at its most stable position, for a 5'5" painter standing. If you sit when you paint it would be fine. I end up having to draw the legs in to get the tray to a suitable height, but the stability is somewhat diminished. Still it was very inexpensive, and very easy to pack. I feel certain that I can figure out to fix these problems, given some time and priority. Or, ask my husband to figure it out since he is better than I at impov. I just need to convince him that it is one of
his priorities
Canvas size is something to consider. These plein-aire painters tend to use little bitty canvases, so when you decide what to buy, also consider the canvas size capacity for what you do..