What is the most efficient layout of track for ascending in a restricted space?

Solution 1:

A larger spiral is most efficient, as you'll have less turns (you can't go up and turn) per straight track piece. For the tightest spiral, 3x3, the number of turns/straight is 1, so you'll only be climbing 50% of the time. With a 15x15 spiral, you'll only need four turns to climb 60 units. This means you can use less booster pieces at the base of each straight section to maintain maximum speed up the spiral.

As for the ratio of booster/normal pieces required to maintain maximum speed up the spiral that shouldn't be too hard to work out with trail and error.

Solution 2:

If you have the gold/redstone to spare, a powered track every other block will keep you at maximum speed for the entire climb.

If gold/redstone expense is a concern, the ratio of powered/regular rails will depend on whether you plan to have unoccupied carts climb the track. If this is the case, two powered rails every 8 blocks will ensure all carts can make it to the top. If you only have occupied carts going up, then one powered rail every 10 blocks should get the carts to the top. Keep in mind this will go much slower, but may still be faster than ladders (your other option for going up/down, now that boat elevators no longer work). Of course, minecart rails have the added benefit of being able to send storage carts up/down too!

I'd also like to note that switches are cheaper resource-wise (stick+cobblestone) than redstone torches (stick+redstone dust) and power rails just as effectively! They can also be switched off and on without breaking/replacing!