A DR will be a whole new world compared to your 125. Torque, Torque, Torque! Being a not-so-experienced rider, you will enjoy riding a fourstroke in the trails. They are VERY easy to ride. A 125 can be a chore to ride in some situations in the woods. There will be more weight involved, but you'll get used to it. The only time I notice the weight of my DRZ is when I have to pick it up off the ground.:o When I went from a 125 to a 250, I said I would never ride a 125 again. When I went from a 250 to my DRZ, I said I would never ride a 250 again. My next bike will be another thumper or a KTM 380...gotta have that torque. Compression braking was VERY noticeable to me at first. I would let off too early and be creeping by the time I got to the turn. Now, I love the compression braking of a fourstroke. For trail riding and light MX, I don't think you will be disappointed with a fourstroke. Thump On!:)