I, like many of you, came up on 2-strokes. I did my time of my XR75 and was faster than all my mates on 80cc 2T's but I never considered anything but a 125 for my next bike (although I got a Yamaha 100, I quickly moved to the 125 Husky). As I got older I move to the 250 and open class but took some time off for education and military. When I became a career military, I took up riding again and got an XR200 because I didn't want to push myself and figured it was a safe and fun toy. I quickly out grew that but after checking my pace to everyone else's, I figured I could make a competitive race bike out of the "toy".
After an Al Baker 220 kit, CR125 suspension, and a truck load of aftermarket parts, my 4-stroke WEAPON was lighter than a CR125 and had more power than either a CR125 or an XR250. To top it off, it was easy to ride and a lot more forgiving than any 2-stroke.
The week before it was to be photographed for a magazine article, then shipped to the Moana Kea 200 Enduro, the engine hand grendaded leaving not much left undamaged from the crank up.
It was replaced with a KX250.
20 years later, after retiring for GNCC's and racing (and the military), I got a new 2006 CRF250F. It was good for the first few months. I absolutely loved the start button, but I was at an extreme disadvantage on the motocross track. I had not adapted to making the 4-stroke go fast and was working it like a 2T. Being out af shape, and generally weaker than my competition, it was all I could do to break into the top 3 - when I should have been running away with it.
At the same time, I began collecting Vintage motocrossers and enduros. I found that I was just as fast on an EVO 1 bike as I was my CRF (except for starting it after a crash). Now, with more the 20 motorcycles, the only 4-stroke I own is my Quad - that I paid $200 bucks - WITH TRAILER!