I found this item on the web which is interesting:
"Enduro legend Geoff Ballard has owned TTR250s since 1999 and can’t get enough of the sweet handling and practical fourstroke. He even scooped a gold medal at the 1999 ISDE riding a TTR250 with minimal modifications. Another Yamaha legend, Stefan Merriman, won the 250cc fourstroke class of the Thumper Nats on a TTR250 too, so this model has genuine race pedigree."
I use to ride with a group of guys on KTM's,I ride my TTR 250, went everywhere and climbed everything they did, if fact they became quite impressed at how well the bike did. The only disadvantage I found was the heavy weight if the TTR, especailly If your struggling and drop it from time to time,can be tiring. Also they would leave me standing when it came to accelerating away,took my TTR a bit of time to get up to speed,even though I had "uncorked" it.
Sad to say I went over to the "DARK SIDE" and now ride a KTM but I passed my TTR on to my son who comes out with us and he loves it! And is holding his own amongst all the "Orange".
He owns it, I maintain it cos he tells me "I got no money" :)
One advantage riding the TTR was going through water,the air box is very well sealed, unlike the KTM's, I'd be far more confident going trough deep water on the TTR than on my KTM!
So in answer to your question the TTR is a great off road bike and exceptionally reliable.
I would say depends on what lev el you want to compete at if its an introduction on a budget then yes.If you want a bike thst can do an enduro then ride to work the next day with nice road manners and little maintenance then the ttr is an excellent choice.