I spent many years racing cross country and pony express challenges (bikes not horses you dopes!) at the top of the game, and I have had too many dirt bikes to name them all including a few years racing on a KDX200, a KTM350, TE610 and the first model KTM380. Depending on the riding you plan to do the biggest differences over the softer DRZ/KLX is ground clearance, suspension quality, and outright power. In the dirt a good rider can win on any bike, but when you get stuck crossing logs on the side of a mountain and a euro clears it where a trail bike gets stuck, or hit a greasy tree root laying angled across a wet clay track and the euro suspension clears it while the trailbike deflects and sends you flying, or you are flying around a corner and find a huge stinky puddle and the extra power of a euro has you easily lift the front tyre and rebound the rear to clear the puddle with minimal wetness whereas the trailbike dives you in head first while your mates laugh. That is where you thank the gods you bought a euro bike and gladly change the oil more often.
From Jonnymac's post, I have got that exact same model Berg. 2003 501FE. Very well built and quite reliable compared to older examples. The 03 is pretty much a copy of the KTMs from the same era, with better suspension and a lighter weight. You can have mine for $3250.

Dont have the time to ride it anymore and has not even been started in 12 months, and looks in better condition than the add.