Having a rating nowhere near the ones you cited I feel I should give you my advice anyhow.
It is quite obvious that there is no barrier, if you are stuck this is surely not due to some quantic jump that you must achieve. It is more likely that your playing skills should keep on following a continuos line, a thing that I gather they've stopped to do.
Maybe you should post you're improvement plan and then ask the Pros where you are making mistakes, I think They would feel more motivation in helping you if you gave them so smaller a task, instead of asking them to make a precise account of all the means they employed in the pursuit of a better rating.
I for my self, not being such a good player as them, would feel more motivated. So motivated I could bring my self to help you, even if clearly don't consider my advice worthy, because I think my humble observations of your present way of study could be useful.
For if it takes a Pro to give a good plan it only takes an average player to point out the weaknesses in your present plan.
I dare say even a non-player who is expert in the art of studying could anyhow enlighten you on your mistakes if you would describe what you are doing now.
Could someone who's like really good like 2100+ (2000 guys can also chime in if they want) tell me how they where able to jump over that big 2000 barrier? My rating has been stuck at 1950-2000ish (but not going over 2000) for a long time. So what did you do to get over that margin? What was your study plan like? What books did you read? How often did you play? What tactics did you do? How many tactics per day?
I'm kind of stuck, and I need some help.