We did a trip several years ago with Antarctica XXI that flew the Drake both ways. Our ship was the Ocean Nova, which was a wonderful size (around 70 passengers IIRC). It does add a bit of stress wondering if the flights will be able to go, but it worked out for us. In our case, there was an impending airline strike that nearly impeded our ability to get to Punta Arenas in the first place. We had to change our flights last minute to head out early to get ahead of the strike, and this turned out to be good because impending bad weather meant we actually flew out to KG Island a day early. Meaning the prior set of folks had to depart a bit early. For us the deciding factor was that we didn't have time to do a longer trip, and saving 4 days of crossings was worth the added uncertainty about flying. I believe there are some options that involve flying one way and going by sea the other, which might be a good compromise if you are on the fence (though it'd be best to fly on the return to maximize the chances of getting there!). As a side note, our trip offered an excellent kayaking program as well as optional snowshoeing hikes -- these were super fun and well worth it. It's an amazing landscape -- you'll have a great time.