I can't recommend MKSA highly enough. They pick up from the Starbucks in Queen's Marketplace which was literally right across the street for us so coming and going - especially once they dropped us back off after 10 p.m. - was the easiest thing in the world.
On the drive up to Mauna Kea, our guide Pat (who might also be the owner or President) was extremely knowledgeable about the local area as he has lived in Hawaii for the past 30 years. He has some definite viewpoints that could be considered "political" but we found them interesting and it added a personal touch to the drive up. We drove up the Saddle Road, passing Parker Ranch lands, the Army training base and lava fields, finally reaching the Visitor's Center. Pat told us about seeing one of the volcano eruptions in the early 80s (I think this is when he said it was) from one of his backcountry tours and reporting it to the local civil defense units. What an experience that must have been!
At the Visitor's Center (9200 feet above sea level), MKSA provides you with a meal and an opportunity to acclimate to the high altitude. I was worried about this trip seeing as how I nearly passed out on Haleakala back in 2007 and had recently had respiratory problems but I need not have feared. While I was a bit slower than others, I just took it really easy and made sure that I was always taking in as much air as possible into my lungs and I was fine.
After eating we climbed back into the van for the remainder of the drive to the top of the summit - 13,800 feet above sea level. Once you leave the visitor's center, the mountain takes on a much starker appearance, looking extremely extraterrestrial (or at least, that's what I thought given the images we've seen of Mars and elsewhere).
Once we reached the top of the summit, we were given a couple of breaths to acclimate once again to this even higher elevation. Immediately it hit me, but I persevered. My husband commented that even he could feel it. We were then given parkas and gloves and while I thought at first I wasn't going to need them, within just a couple of minutes it was FREEZING and my hands would go numb without the gloves. After learning about each of the observatories and their various equipments, we climbed back in the van to drive over to where we'd watch the sun set and look through the telescope provided by MKSA.
Then we made our way back down the mountain to an area around the visitor center where we had an astronomy lesson from Pat that was just astounding to someone that knows absolutely nothing about stars or the galaxy. My public school education skipped right over that part of the curriculum it seems. Through their telescopes we got to see galaxies, constellations (I can now unequivocally point out Orions Belt), and to close out the night the rings of Saturn. It was just magnificent and awe-inspiring.
I immediately fell asleep after getting back in the van, so I can't comment on the rest of the drive, but I can comment on MKAS - if you're going to Hawaii, definitely book this trip. This, the manta ray night snorkel, and hiking Kileau Iki trail are three experiences you don't want to miss.