Sometimes when I pull up an option chain in IB, it takes a long time to load and sometimes sections of the chain will never load. I end up having to exit whatever product that I am looking at and open it up again. Sometimes I just give up. Really annoying. With ThinkOrSwim, all option prices load instantly, never partially, never any lag. I figure that IB probably made some design trade-offs favoring flexibility over optimizing this particular case, but how much would it really cost them to fix this issue?