I had an Eclipse expandable tail trunk (I forget the model #, but they call it the Rumbleback Seatpack). The bungee cords hooked on nicely to the Frankenstein bungee bolts on my Bandit. I did however lose the bag one day
as I think I forgot to hook the bungee cords to the bike - I sat it on the rear seat, put my helmet and gloves on, started the bike, then got on and rode off. 45 minutes later, I get off and no bag. I ride all the way home thinking it fell of somewhere in the parking lot, but I never found it. Only lost the bag, a disk lock, an extra helmet visor, and the liner to my JR Atomic jacket. Anyway, I now have a Joe Rocket tail pack, which is a little bigger, comes with a more convenient handle on top, and includes a shoulder strap that clips on when you need it. I like it alot. Unless I'm travelling two-up, I'd prefer a tailpack to a tankbag (ACK! scratches!). For all-day (12 to 16 hour) rides on the interstate, though, I think I'd prefer a huge tankbag that I can rest on occaisionally. Although if I'm travelling that far, I'll probably have the tailpack, too, along with the saddlebags. Anyway, as long as it is big enough for what you want to carry, the Chase Harper, Eclipse or Joe Rocket tailpacks are all great choices. There are also some others that probably shouldn't be overlooked (TourMaster, Wolfman???, RKA).