Okay, my finger already hurts 
I know, that you already have cherry mx blues. Anyways, i find that topic interesting, so I post my thaughts:
I've tried a few Keyboards. Here is my Ranking beginning with the WORST (was a surprise for me
MX Black < White ALPS < Rubberdome
So rubberdome are the best so far as I tend so slam the Keys. The actuation at the bottom comes in handy here. I'm typing on it right now: cough...
Black ALPS and my brand-new(old)Blue ALPS to come...
It is still good that we have people who try and test the game. Not everyone has every kind of switch type available.
In my experience I have tried several rubber domes, mx blues and mxbrowns. The order is Mxbrowns > MxBlues > Rubber domes. MxBrown being the best I have tried.
I have been playing rhythm games for about 4 years in total now, and here is what I have learned regarding keyboards from experience.
The rubber domes aren't so bad if they are good quality rubber domes and if they are new. Once the rubber gets old though, no matter how good quality the keyboard is the 'feel' changes. Another thing that is not ideal about rubber domes is that there is a tendency for the feel of each key press to be different. In mechanical keyboards a key press feel is pretty much the same all through out the board and even as the board ages it doesn't change as much.
One more thing that can be said about rubber domes and I consider this as the most relevant to rhythm games is that the key activates at the bottom, unlike mechanical switches where the 'actuation' point (I hope I am using the term right) is near the top of the press. Rhythm games are very much dependent on the how quick the player can react to a game. In many cases they require you to press a key at the same time a command appears on screen -- and within milliseconds of timing difference from a "cool" rating to a "perfect" rating. (@Badkarma please correct me if this is not the case with osu) And the microsecond of difference relies on the distance between your finger can press the button, and the distance the button travels up until it actuates.
What players usually does, is they adjust when they press the key... long time players do this consciously and new players do this unconsciously... they press the key earlier by a few milliseconds than the supposed "perfect" timing - and when the key actually actuates.. then "perfect". This is more noticeable in slow bpms than in fast bpms.
But nothing really beats the 1:1 ratio of when you press the key - the key actuates. Although this is still not the case with mechanical keyboards it is definitely better than with rubber domes where the key actuates at the bottom. Even if the player actually still bottoms out the mechanical switches while playing, it really helps the timing of the player since it moves the 'actuation' point closer to when the player actually presses the key. This makes timing a lot more easier than having to account for the travel distance of the key.
Other people may have different experiences with this I am not sure.
The reset problem with blues however is its weak point when it comes to rhythm games. As mentioned in one of the posts above, in order to be totally sure - the key has to be released totally for mxblues. This is quite a problem when spamming keys as you have to raise your finger more than when you are using mxreds or mxblacks. For blues there are times that the key can be actuated without having to reset the click part but if @Badkarma can back me up on this - this is not really a 'stable' way of pressing the mxblue keys. The problem is still present a bit with mxbrowns but not as much since there is no mechanism for the 'click' sound for the mxbrowns. In my theory the mxreds will eliminate this totally because you can pretty much leave the key depressed a bit above when the key activates.. and then just 'vibrate' (for lack of a better term) your finger and it will spam better.
I will try once I get my hands on mx reds. (Any donations will be much appreciated)
