Sorry to resurrect but wanted to add info for people researching this like I was.
The diagram bean drew is exaggerated, makes sense, but is also biased toward the case of using the bandit head over the dot.
I am looking at both cylinder heads as I type. It's impossible to capture in pictures but easier to measure and post. The B12 combustion chamber offsets into the bore by about 2mm all around. The difference between the dot and B12 chamber diameters are about 4mm so you can say the dot offset will be 4mm around.
The pros and cons of a squish band around the bore (versus a squish pad like between the intake and exhaust valves) is another story. Neither the Bandit nor the dot heads line up perfectly with the bore.
On the other hand, if you take the Bandit head and skim it, the diameter will get smaller. The only way it wouldn't would be to imply that there is a section of the chamber where the walls are vertical, which doesn't exist.
The major difference between the chambers is as mentioned, the depth. Skimming the bandit head will obviously make it shallower but it will also shrink the diameter leading to enlargement of the squish band, NOT what was drawn in the illustration.
Aside from that data, as far as I know having a squish "band" is not a bad thing at all. How much of a band is something that I haven't looked much into.
Just wanted to clear that whole thing up as I have both heads sitting in front of me.
