I have an ATK305 Indonesian model from '07 that I bought recently off eBay. I also have an ATK300 made in Korea in '95. The most apparent difference is in the finish coat on the necks. The 300 has a thick lacquer gloss finish, and the 305 has a satin finish. The 305 electronics are very smooth, and has great diversity in tone. My bass instructor played it for awhile and was very impressed with the sound and feel of the bass. He plays an expensive Yamaha 5-string, which costs about a $1000 more than the ATK, so the fact that he liked it so much made me feel good about buying it. I should mention that I haven't done any adjusting to the action, or intonation, and it sounds great right out of the case.
As with all basses in this price range, you may have to make some adjustments, and change the strings to suit your style, which is something we all do. But, I think the ATK's are a great bass for the money. My only regret is I'm lefthanded, and can't find a lefthanded ATK305. The ATK305 I recently bought is a righty, which if I can't find a lefty, will one day be parted out and put on a lefty body that I'll have to make myself!
Buy one, you'll be glad you did. I get lots of compliments on my Amber colored '95, and especially because of that big, chrome plated pickup/bridge guard. That's why I bought it. It gets noticed for both!