Right, the 55g one feels amazing despite being the heaviest for me. I can get into a great rhythm with them. And you’re right, I probably shouldn’t try changing both sliders and domes at the same time, although ngl I’m already dreading multiple teardowns. Upon further introspection, the HHKB is my first plastic plate-plastic house board–everything else was steel plate, plastic house (Leopolds, Realforces).
Another vote for typing angle being a factor, as @fatalruin was saying. The stock HHKB typing angle seems steeper than 660C (unconfirmed, haven’t found a spec sheet yet.)
The homing/layout idea you’re mentioning with the JIS vs. ANSI stagger is interesting. So on my 91U, it did take me a few weeks to adapt (I am not admittedly using it as a JIS board on MacOS), but I don’t have any misfires now–just on the num row where the characters don’t correspond to the printed keys, but it’s nbd.
How would I confirm the stagger differences between my two boards (I don’t have a caliper?)
I don’t believe the Topre caps are SS2–I have those caps from a 660M and 980M, and those are definitely lower. But the particular caps in that all-gray colorway feel off compared to the blue-and-gray or even the black-on-black (which I also own.) Someone correct me but I believe the Topre Leopolds do not have SS2 height caps.