Got to give KTM credit they've been working HARD on their bikes for a long time to get to this point. Complete design change in..... what was it 98? Then engine work and their latest, their suspension set-up by dropping the PDS.
Now, I'll be waiting to see their SX line come out with an Aluminum frame in the next few years.... and not because it's superior to Steel but to public pressure.
I had the first resign on the 125sx, 1998 just like you said. I had several other friends with 125s at the time. The KTM was clearly superior in the motor dept, handling was not there at that time but I think nowadays it's as good as anything.
Go to any off road race around here and it's a sea of orange with some red, blue, yellow and green dots here and there.