No bug report in this post--just iCab & MacOS 9 babble
I've played with iCab a few times. It was highly regarded in some circles years back. But it never worked very well for me. The current iCab--the one for OS X only--did appear to be decent the one time I saw it. Although that's a different product--it's WebKit based.
For people with a "new" enough Classic MacOS system, the best choice for reasonably current browser is Classilla. It's based on Mozilla code, and it's actively being developed.
I've tried it on my Power Macintosh 7600 (with OS 8.6, a G3, and nearly 100MB memory). It appears to have good page rendering, but--on that machine--it's definitely sluggish. A newer computer would probably fix that. But the newer you go, the easier it becomes to run OS X.
Still, I like the Classilla project. There is a part of me that hates computer upgrades and hates the constant parade of whiny little voices telling me I need to buy something new. Anything that can keep something old running is a good thing. Then, there are people who have stuck with OS 9 for whatever reason. (I heard of one person running a graphics business who'd stuck with OS 9--he was tired of spending money for new graphics software, and he probably knew the stuff he had in and out making him more productive.) People like this could possibly use a reasonably modern browser.