if you have one - tell me about them. good or bad!

my LO (almost 1!) has the older style fisher price space saver high chair, which has served us well, but doesn't fit under the table (so she can't join us at the table). in addition, she can shove off the table and almost flips over backward.

I like the idea of a hook on seat (because even if I get a "shorter" high chair, she could still push off the table) but they scare me! ha! how secure are they?