Wilton has ones with fine tips now. They work a lot better than their old ones. However, I had mine out tonight and they're useless. Every single one is dried up. I've had them less than a year.
My Americolor set is still going strong 2 years later. I wonder they expire? Hmmmm. I need to check into that. Anyway, the Americolor tips aren't as fine as Wilton's but they seem to last longer. On the other hand, with a 40% off coupon you can buy Wilton a couple of times before you get to the cost of Americolor, but you'll get less colors in the pack.