zigzag:
To get back to your question about "spinning out" at speed. 2p worth.
I think the way to work it out is to consider how fast you actually want to go at your preferred maximum cadence.
For example, I am most comfortable at 90-100rpm but I can spin 120rpm downhill without too much trouble - faster is difficult with heavy legs!
Uphill, I can usually do about 15kph at 4% - 34 inches at 100rpm - or 11kph at 6% - 29 inches at 85 rpm. (~230W - I am not a racer!).
Level about 32kph - 78 inches at 100rpm (also ~230W)
Downhill depends on how steep and how fast I want to go. 120 inches at 120 rpm gives almost 70kph (180W and -8%) - plenty fast enough.
Hence my choice of a set of ratios from ~29 to ~120 inches.
With a triple in this range (53/39/30,12-27) the steps are approximately: 117,108,100,94,87,83,79,73,67,64,60,54,49,42,37,33,29 inches. 17 effective steps on 3 chainrings.
With an 11 speed compact double in this range (50/34,11-32) the steps are approximately: 120,110,101,94,88,81,78,75,69,64,60,53,47,42,38,33,28 inches. Also 17 effective steps on 2 chainrings. So far, it seems that the double shifts better and getting the right ratio is easier than on the triple.
With such a similar set of rations, the compact double seems, to my mind, the better choice.