Wanted to update that I received my FC660c and have been using it.
Impressions:
Out of the box even though it is still topre, it feels worlds different to my HHKB and to my memory it has the same character as the Realforce 87u, it is slightly different in feel and sound.
At the current point in time I cant say whether i prefer the HHKB or FC, the two boards are similar yet so different. But I do understand more why people say the HHKB feels cheap in comparison the plate mounted boards, there is def a huge difference in feel.
One thing that has been bothering the hell out of me is the left shift. The profile of the key seems so out of whack to my HHKB. It is retardedly high. Because it is so high, when I use my pinky to type my "a" key, my pinky brushes against the left shift causing unwanted spring noise. Even the slightest touch on the shift key will produce sound. So in my quiet room, it ****ing irks me to no end. Maybe lubing will help alleviate this, which I am too lazy to do right now but I am sure in time I will rip the board apart and mod it.
In terms of noise, HHKB is vastly louder. There is much more plastic clackity-clack going on from the HHKB. The FC660c while lower in volume, I almost feel like there is more thock from it because there is less plastic noise.
I was scared that I wouldnt like the FC since I have been using my HHKB for so long, but I am glad that I made the purchase. If you were to ask which one I prefer, I honestly cant say. It would be like asking if I prefer blonde's to brunettes.
Oh and lastly, the board is def higher than 45g weight. It really feels like 53g, its only a touch lighter than my 55g HHKB.