Yeah, I got turned off by them as far as anything requiring parts, but I had a deal on credit card or something and couldn't pass it up. Really, the Sears pro router is quite good, so far. I guess as long as I don't need parts for it, I'm good!
My Porter Cable that broke was a little 6902, and I could get a part, but it probably isn't worth it - the base as well as the fine adjustment was broken when it was given to me and it was only good for hanging under a table; lacking a lift, I had enough of the base for that. But then I couldn't get it to clamp up. I don't know if I somehow cross-threaded the clamp screw or what but I ended up breaking the stupid thing.
So yeah, I'll likely just shim as you said. I THINK I can adjust the Sears router from atop the table, I gotta check the manual!