I could say tons about the relative advantages, disadvantages, compensating elements of each of these, or regarding what actually function as--in essence--virtual or on-line communities, but that, alas, is for another day.
I did attain 1800+ at chessCube tonight. Hard to say, but its probably like 1600 in 5-minute chess at ICC. For sure it is inflated, but not WAY inflated. But if any of you have played 5 0 at ICC, you know that even 1500 is no laughing matter, which no less a blogger than wormwood, I am quite certain of, could safely attest to.
5-minute was a game that I used to be afraid of, for sure, but in due time, I had begun to see my advantage. My openings are all mapped out; I can pre-move; and faster than most (but not all), often whipping out tabaya's in 20 seconds or less. Whereas before beating 1700's was not common and 1800's most rare, now I am routinely beating 1800's.
Compare to ICC? Why yes, you will have that. But not today. I did so much work in chessBase9 on my prep, in virtually ALL lines, that I had to take a break there, with, what, chessCube as a low ego stakes game, or venue. Reporting there is worse than dying, whereas ICC is a svelte pipeline straight into chessbase, so I can play late, or tired at chessCube, and not get all hopped up inside, feeling like I need to chart the heavens after, like Laplace charting hyperspace or Euler explicating complex analysis. No, 'just chess, nothing else', like in the beer commercial.
The board there is slick; the interface truly sucks . How they fail to learn or see, is beyond me, and I am speechless. Again, long story. Best summed up another day so other chess players can compare...
Me? I have a serious illness. My body is not dying. No guesses, please. If you read between the lines in the photo, age 52 and all, with my lovely and dear girlfriend Courtney, still 39 bless her heart, what a thing to still be '30!' I tell her, if you read between the lines with all my beets, cabbage, organic meat, carrots, string beans, black bean, rice, gluten and dairy free, you will witness an usual specimen for his age, running and stretching, a nutrition advertisement but things DO happen in life and in my own way, I am fighting for my life.
Love to all beings, dk
 Any of you who know me, know that I NEVER say 'suck' but it sucks. Believe me.