I've had my PortalPro II for about six years, and I still would buy another. It's so much more stable and easy to set up and transport than the others I've tried. I love that I can use a simple carbiner clip to attach a small pack with my iPod speakers, facecradle covers, etc. to the chair frame itself and then zip the whole thing neatly into it's carry case and wheel everything with no effort instead of lugging it over my shoulder.
It fits neatly into the trunk of both sedans and my SUV...it even fit in the passenger seat of my 2-seater. The Earthlite folds small, but it is a thick, wide package and didn't roll around.
The nylon armrest strap never bothered me, but that the attachment hardware underneath the armrest was made of plastic did...no matter how you try to prevent it, some powerful, big guys WILL push down on the armrest, and one day it finally broke. I just looped the strap under the arm bar and rethreaded it up into the adjustment clip to use the chair until Oakworks to sent me (free) the new metal part that is now used.
I've replaced the wheels and patched a very small cut in the UltraTouch vinyl and that's the only other maintainence this hard-working chair has needed. Clients always coment on how much more comfortable it is than other chairs they've tried. Note that I did replace the standard foam inside the face cradle with CORE foam, a Tempurpedic-type product, and that instead of the standard flat pad I use the wedge-shaped sternum pad vertically; with pregnant or overweight clients I turn it horizontally.
For those clients with knee issues, I just have them sit on it as if it were a chair, with legs forward instead folded under them, and bring the face cradle up to allow a comfortable more upright position.
The wheel placement did bother me a bit in the first months of use but my feet quickly learned where to step without the need to look down.