I take my Fuji MX-200 atb on the same 30+ mile loop the SS/FG & road bike goes on. It's 15 miles each way with several hours in between to be the tourist. Add roughly 10-20 minutes to the ride and while it's a extra time with a slightly harder workout for the legs, the rest of the ride is more comfortable, so the ride is just fine. I find for errands, the atb is the truck of bicycles. Handles a bigger payload and is more stable to ride while carrying a bag and still steering with the same hand. After riding the atb, riding the others seems to be easier going. So the heavy sled is better to train for using the others and get in shape for me. Probably because I'm hammering away at it for those extra minutes. I'd say that's more a positive long term effect.