B-12 chemtool is the strongest stuff I've stumbled across for in-tank additives. Acetone is a great cleaner, and B12 has a good bit of it. So it's better as a quick cleaner instead of something that is going to sit in the tank for a week or more since it's not too happy to play with plastics. Techron fuel injector cleaner is kind of crap in my opinion, so if you use the Techron, make sure it's system cleaner as it is much more concentrated. The B12 is more solvent based, and will clean the nastier grime out of the ends of the injectors better and helps to remove some moisture if present.
In my experience, if it's a fuel nastiness problem and B12 doesn't help you, no additive will.
The Concentrate is the only one to use. The regular Techron Fuel Injector Cleaner is not the strong stuff.
I don't know how it compares to B12, but I do have pretty good info that it does what needs to be done.
That may not be it at all, so if you aren't getting any improvements I would check the condition of the air filter and snorkel opening for obstruction, and possibly check the plug. It's usually uncommon, but I have heard of the CBR having plug failures. It's in here somewhere...