Re jumps ,percentage wise I'm fine touring with the percentage jumps on my 11-34 nine speed cassette, which while I don't have the chart in front of me, has maximum jumps of 15% I think, which is fine for touring.
However my wife's ten speed 11-36 has slightly smaller percentage jumps, which is great, why not take smaller jumps now that ten speed is old, reliable and available?
for me the 17,18,20% jumps are a pain in the arse.