Do not give up so easily on these posts, Amy. They are great posts, but you seem to lose confidence a wee bit much. I hate to see that because you know very well your creations are worth something. Now, all ya got to do is get past the limitations of the game, or your unwillingness to continue.
(It happens to all of us with a project, or even in real life).
About the MCBR, usually, when I make one (it varies), I usually have four to five consecutive brake pieces, each lowering in speed (if you so choose) or, one track brake piece, one normal piece, two more brake pieces, and either another regular track section and one more brakes section, or just down into the drop.
I would say, it probably does not matter how many you have if you stay within the realms of 4-7 MCBR pieces.
I do hope you find enough encouragement and a will to finish this project. I for one, love seeing them. Especially from you. So, 'good luck' if ya decide to take this challenge back on, and 'oh well, there is next time' if you do not.