the ten speed 11-36 is actually a pretty nice cassette in terms of jumps. my wifes bike has it and compared to my 9 speed 11-34, the jumps are just a bit closer in places, and you still have 36 over a 34. A great touring setup, and then of course, as you say, you have the 40, 42 and larger cassettes , especially with 11 speed, that still will, Im sure, have reasonable jumps between shifts.
10 spd is the new 9 spd in terms of price/performance , and I presume, longevity,