I actually learned what a Hemato is from a Little Giant ladder once and havent climbed on one of them since that incident. Please you guys, double check those latches before use.
I am not recommending you do it, cause you might bust your butt. I have installed signs, painted stripes, and installed storefront vinyl (as well as drywall, finishing, ceiling grid and tiles) from drywall stilts for years. I even still have my double set out in the shop that I made out of two sets to reach even higher. Stilts take a lot of practice, but it can be safely done after putting in the time, and I am proof. You've touched on some of the pros... they can be tossed in a car and carried to the job, they are cheap, they work on a variety of surfaces (with practice), they are quick to setup and use.
What I DO recommend is that you look into buying a "baker" scaffold (also mainly a drywall tool). These are strong, secure, cheap, and can even be safely scooted along from above by the user (with practice) on a level, smooth floor or parking lot.