Yeah my kit lens is a 18-55mm, no USM, no IS. I personally don't know enough to comment on how bad it is.. but thats the word out there. I got a decent deal for the new camera and kit lens on eBay, really the only reason I have this lens.
That 100mm looks pretty nice i'm debating that one. I think i'll hold off until my bank account recovers and for now replace the kit lens.
I've seen a few of the 100mm's on eBay this week finalize at $450 used to $500 new, it's worth a look.
eBay can be sketchy but can work well too. I was selling an old sony point and shoot last week and nearly got scammed pretty bad.. fortunately I sniffed that out before I could lose anything.