Agreed on the notes above. I traveled Space A quite a bit on AD and some as a retiree, which has a lower priority.
The best way to do it, for me, was if I had, say, a 30-day window of leave in between PCS duty stations, and decided to throw myself into the serendipity of what was available. You have to be prepared to wait, wait and wait, either in the terminal or wherever you found a room overnight, via remote check-in. That’s not a fun way to spend precious leave, or you need to spend $$ for food and lodging, off-base or on. The biggest challenge is the end game - getting back to where you want to be by a desired date. I admit that was what always caused me the biggest anxiety (military life creates a horror of “missing ship’s movement” and the very real penalties for being late and not planning well). About 6 days before I needed to be back, and I always built in at least a 2-day cushion at destination end, I would start working the trip home. I also knew I had to be prepared to fire up the charge card to buy last-minute commercial air, never the cheapest time to buy. You have to travel light with clothes and outerwear that work for wherever you end up, plus a stash of emergency power bars.
The flights can be spartan. Seat location choice can be limited. Amenities are limited.
That said, I had some great Space A adventures. There is a community of savvy Space A travelers who know all the strategies and tactics. During one PCS 30-day window I made it to both Naples, Italy, and Japan, with 2 days in Hawai’i. I was young and indestructible then. I can still fall asleep anywhere, but feel it more these days when I wake up.
You can find guides to Space A travel on Amazon, and no doubt travel blog websites.