It's hard to compare due to the inherit cheapness of membranes. They degrade at different paces depending on material. But for the most part most membrane domes are in the 40-55g area but again it's inconsistent.
Ironically after my mx blue filco broke in an accident. I went back to a Microsoft internet pro(2003-2004 membrane dome, surprisingly good quality at least body and key cap wise) I had that was well worn. It felt horrible, inconsistent, and not smooth. The black's despite their negatives for typing are MUCH better than your standard keyboard domes.
They are linear, some would say progressive. They subtly increase in resistance starting at 40cN, actuating at 60cN, and bottoming out at 80cN. They are very smooth, almost no hysteresis, and are sensitive despite their resistive and heavy nature they can be surprisingly sensitive. I guess it's probably because they are the most simplistic or at least considering to be one of the most simplistic of the cherry brand. The resistance is subtle but there it's very shadowy at times, some say it's not there but that's not true.
They are sorta of a two-face switch. Typing softly without bottoming out makes you very tired and fatiguing to the fingers but punching through to the bottom doesn't really fatigue in my case at least until a much later time. I will say that while I like the switch and they are nice, they can be burdensome and tiring plus inconsistent. Sometimes you fly on them, other times they feel like quicksand except smoothly. And sometimes they feel like they come up too fast pushing you finger up and sometimes too slowly, it's very strange it's more noticeable early on at least for me before getting used to them and loosening up.
The heavy/resistive nature of them not just for typing but gaming can sometimes be bad. I notice that at times I would misjudge the required strength and would not actuate the switch. I guess it could be my fault I do have a bit of a heavy handed touch though I have control to type softer. I guess it be nice to test out the mx reds. I mean they do rock for FPS gaming but sometimes it can be a bit much. RTS I've seen some complaints on them being too heavy/resistive. Most of the mx black users seem to be FPS gamers or gamers where quick, consistent key presses are not needed at least for extended periods of time.
Right now I'm on the mx browns. Many consider them a middle ground between typing and gaming. But....
I don't want to give recommendations, I sometimes feel like I give out an idea and the person jumps with it without researching. I'm not saying the black's are not worth the buy but try and secure a cheaper mx black keyboard like 20-30 dollar mx black and see if you like it. Because the blacks are and I do agree, to some extent of the negatives; I don't hate them but I do have issues with them at times.
It's a switch that is very dependent on mood and energy. Sometimes they feel awesome and it's spectacular and then later in the day they are just the polar opposite and you hate them and are so tiring and whatnot. Not to say what will happen to you is the same as me but if your worried I'd be careful.
Also speaking on their break-in period. I'd say to loosen up is about a normal as other switch 1-2 weeks. But fully break-in can take months if not years, I've noticed when I did use them that they felt a bit lighter since I bought them around 6-8 months ago.
