I started with 4 hours, then took a break... now I have nearly 1.8k hours...
As for maining, huh. Gyrocopter is really fun, so are the 'skilly' heroes such as Invoker, Meepo or Chen, but it's also fun to come back to the basics as Drow, Phantom Assassin, Anti Mage or Wraith King. That said, I tend to play a lot Templar Assassin lately so yeah. I change mains every 3 or so months, can't tell what I'll be playing next.
Sadly, I play on EU/US servers. I once tried OCE but the ping is unbearable.