I currently have a $600 Trek MTB that I take just about anywhere, but I'm still a bit challenged in some of the climbs in my area. When I'm on the road, I don't use the granny 22. I stay at the 32 with the 28 rear. Of course if it's really steep for me, especially off road, I do use my granny gear. I'm 5'9" at 175 with a GUT... and have a goal of losing all this gut and about 15 lbs. Now how much of a difference is it using a road bike on climbs that are under 20 lbs with a Compact and 11-28 gearing versus a 29 lbs (or maybe even 30) using only 42/32 front with 11-28 gearing?