Really depends on the type of riding you do or want to do. I have a Surly Long Haul Trucker that I use mostly for road touring. I can load up the racks and ride it all day, no problem. It can handle gravel, jeep trails, hard dirt pretty well. Not so great on techy singletracks and sand. For bikepacking I use my HT 29er which is a lot more fun. My wife has a Fargo with two sets of tires, skinny ones for when we road tour and fat ones when we take the trails.
If you're happy with the Hardrock you might first want to try a second set of tires before investing in a new bike.
- Right on. I do have some Kenda Couriers that i throw on occasionally. The Long Haul Trucker is bad ass man, had the pleasure of riding my buddy's. Next bike is either the pugsley or LHT - down here the touring options are endless. thanks for the reply!