Before people like Noctua came on the scene I used a lot of the Sunon Maglev fans for low noise operation. They work well, and last a long time, but I'm not aware of new and improved generations of fan from Sunon. I think they concentrate on industrial applications now, where noise isn't the key issue.
dBs don't tell the whole story. Some fans score well on noise level, but the noise is a bearing whine that, even though faint, really grates on the nerves. Both Noctua and the Sunon Maglev fans do a good job there.