Jebo (small one) - very noisy since day one. Powerful? Well, I can accept it but as it becomes older, it's so noisy that I have to send it for retirement permanently after several attempts to clean & oil it.

Jebo (twin fans) - very quiet compare with the single fan one. I find it not powerful and getting worse as it gets old. I have 2 of these. After several years....1st set got a damaged fan (meaning only 1 of the twin fans is working). 2nd set is working but totally not powerful.


Mr. Aqua Super Tornado Cooling Fan - In terms of noise level, this is the best option so far - very quiet indeed. It's so quiet that I thought it was not turned on. It's not as powerful as Ista's but in comparison with Jebo's, it's very good. It's rather bulky and heavy though.


Dymax fan - I was told by the LFS that the quality is uncertain. It may last only 3-4 months if you're unlucky. I did not bother to check it out after hearing such comment from the LFS.
I have tried another fans which I cannot remember the brand - it is white colour and the box has Japanese words. It is totally not powerful at all.