After numerous trips, both solo, double, and more, I've come up with what's best for me and advice I've given newer riders. Short trips are a great way to gauge riding/travelling compatibility. This way there is no guilt and martyrdom on a long trip. If you find you and your buddy are similar after that, you've got a low stress trip. Another style that I have found works great is just meet your fellow companion(s) at a destination. You get to ride at your own pace, your own route, etc. The destination doesn't have to be a daily one either. On a long trip, you can meet up every couple of days.
All that being said, my favorite rides have been the solo rides. No compromises, plus best of all, you meet more people which is half the reason I travel.