Yes. Yes you will be in 2nd or 3rd gear most of the time in the mountains. I used to go skiing all the time in my Honda, and having to downshift for a long pull occasionally was less than a problem to me. It's the long highway 5th gear pulls that make it worthwhile.

5th gear at 55mph is around 1800 rpms. Meaning that cruising at highway speeds, your car is barely burning any fuel, thus the great mileage. You WILL NOT BE ABLE TO PASS ANYONE in any gear BUT second, which will take you to 84mph at red line with a dx motor and ecu. I know for a fact that at 7000 rpms in 3rd gear, you would be traveling 135mph, IF you can make enough power to overcome the wind resistance. I did it on a dyno, so that's how I know.

Learning to drive with this transmission on any variety of torqueless d-series engines can be challenging, but once you figure out that if you keep it wound up (like an early S2000) to make enough power to get out of its own way, it's extremely driveable, and in some cases even advantageous due to the lack of shifting needed. It's sort-of a 1-2-5 kind of setup, but I still used 3 & 4 anyway.

Engineering catastrophe or not, it's actually got great purpose when big auto is still only cranking 30 mpg out of new cars. The cx and vx trannies are almost the same. The engines are very different. The red line on the cx is 1900 rpms less than any 16-valve honda engine, and surprisingly, both of the 1.5L 8-valve engines make a lot of low-end torque in comparison to their 16v counterparts, which allowed these transmissions to work well. That's why it's like driving a car in Gran Tourismo after you've played with (and screwed up) the gear ratios. The advantage of the screwed up gear ratios = really flippin' awesome gas mileage.