I miss business travel to some degree. I saw so many interesting places, especially in all my Asian travels. People were fascinating and so hospitable; food was awesome. If I had a day off or a weekend, one of my hosts or local coworkers would always take me sightseeing, or better yet, just take me around to a bunch of local places. I always asked to eat at "their favorite neighborhood place," which always led to some very memorable experiences.
Yes, the work part was usually stressful and sometimes cast a dark cloud over the whole experience, especially if I was visiting a not-so-happy customer. I don't miss writing trip reports over the Aleutians, or the constant jet lag, or the immigration line at O'Hare. But I do miss the people, places, food, 5-star hotels, business class... all on Megacorp's nickel. I feel quite fortunate to have seen so many places.