I have a specific question related to pony tank sizes and air travel. I'm not looking to open up another discussion about if ponies are a good idea, or the calculations, or TSA requirements. What I could use advice on is the practical experience of air travel with a 13 vs 19. Either size should be adequate for my depths, but a 19 would be better, and I hear they sling better too which is what I would do. I'm typically pushing weight limits more than volume when I fly, but the 19 seems like it would be bulky in a suitcase. Weight difference is only ~2 pounds, but I'll be shuffling gear to stay under 50 pounds not to mention the airlines at 40. Could anyone offer their experience on traveling with both? I'd grab a 19 for my local diving all day, but I don't want to buy two. I'm leaning towards the 19 and figuring it out, but would be interested if anyone says it's a headache. Thanks!