We have the First Years high chair/booster. It's similar to the Fisher Price and straps onto the kitchen chair. Overall, it was great because we didn't have the room for a high chair. It was portable, too, which I really liked. The downside was that every time I took it off the kitchen chair, it was terrifying how much crud was underneath it. Tyler just so happened to refuse to use a booster seat when he gave up the high chair, so we never got to use that feature, but I think it would be useful. Also, be careful if you have painted wood chairs, we had it strapped on pretty tight and it rubbed the paint off some parts of the chair.
I don't know about using the actual table top. That's a LOT of room for messes to spread once he starts self feeding. Personally, I liked having a tray to keep his mess contained to one specific area, and the lip on the tray helped keep finger foods off the floor, at least a little bit.
