We considered the Stokke and ended up buying the Svan. LIke the Stokke it is cool-looking and compact and can be adjusted for older children. The difference is that the Svan comes with a tray so the child does not always have to sit at the table, although they can. I would have hated to not have the tray--my DS takes FOREVER to eat, and I hate to leave him alone at the table, so I will often pull the highchair into the center of the kitchen so I can do dishes, cook, or whatever, and he can still be eating. (We do eat dinner as a family, but not always breakfast and lunch.) I was also concerned about the Stokke tipping over. I know nothing about the Keekaroo so I can't speak to that.
Another thing to consider: my mom bought a Fisher Price high chair for her house, at a cost of approximately 1/4 of what we paid for the Svan. It is big and plastic and a total eyesore, and I don't wish I had it. BUT it has a lot of features that are really convenient: it's on wheels, the seat is cushy and adjustable, it folds up, and most importantly the tray is HUGE and easy to get on and off with one hand. So if you have the space and don't care about aesthetics, you can save a bunch of $$ by just buying a traditional high chair.