Well, the first thing you have to understand is that one overriding factor in bicycle component manufacturing is marketing. Manufacturers are always looking to come out with something "better" though to them "better" just means better selling not necessarily better functioning.
The big problem with this is that old stuff becomes obsolete even though it may work just as good - and in a few cases better - as the new stuff. The big things these days is stiffness. Stiffness is better because, well, of course it's better, right? More is better, right? In a crank that's probably right but really, how stiff do you need? I'm just not strong enough to flex a good square-taper, let alone anything else. I have Hollowtech II cranks on my MTB but I can't tell any difference. I have an ISIS on another bike. Seems the same to me.
Your biggest problem is that Shimano only made the Octalink for a few years and they were the only one making it. he day may well come soon when they simply don't make them any more and nobody else can and I can't see Shimano letting anyone else make them for a LONG time. On the scale of decades. So there's a good chance that someday you could be SOL if you need to replace the thing. Maybe you could find one on Ebay. Probably.
Really, the only thing that looks like it won't be completely replaced by integrated-BB cranks is square-taper. They work fine. Dunno what your issue was with your BB but I have three bikes in my garage with square-tapers that are over 20 years old. A quality square-taper will last as long as anything. The best BBs on the planet are made by Phil Wood. They only make square taper.
Three basic types: square taper, splined (Octalink and ISIS) and integrated/external bearing. Supposedly going down that list each is stiffer than that that came before. Only advantage of integrated is that they're REALLY easy to pull on and off. Flip side of that is that they're really sensitive to side-load on the bearings. So in that way they're almost a step back. With cartridge bearing square-taper and splined BBs you didn't have to worry about correctly loading the bearings like you did with loose-bearing models. With the new stuff you do. So really if you don't know what you're doing with them they just make it a lot easier to F it up!
All of this IS confusing and it IS a bummer. Heck, I would be surprised if in the future people aren't throwing out perfectly good integrated-BB cranks simply because they can't get the right bearings anymore. The bike industry views today's latest-and-greatest as tomorrow's useless junk. That's a shame - especially when tomorrow's useless junk is being made to a fantastically high standard by Campy, Shimano, FSA, etc. etc. It's great stuff. It's such a shame that all those companies will try to get you to throw it away next year.
Chris
Last edited by GV27; 02-07-09 at 10:29 PM.