Those New GDS-2000A scopes comes with Hypro bearing fan.

[Kiriakos GR]

Hypro bearing is one of the latest developments in electric fans manufacturing.

While sleeve fans has a quieter operation regarding noise coming from their mechanical parts,
ball bearing fans was always the best bet for CPU fans ( INTEL ) that fan long life is important.

Those Hypro bearing are one further improved design which become known some years back when an hard drives manufacturer made use of similar technology in their top product line of hard drives.

In the year 2008, ADDA from Taiwan which is a dedicated manufacturer for fans and cooling, presented their version of Hypro bearing fans.   http://www.adda.com.tw/tech.php?no=7

GW Instek use those  AD0612DX-C70GL Hypro bearing fan in their GDS-2000A scopes.
And possibly they did it by choice due their slogan : SIMPLY RELIABLE. 

While the fan noise due the blades is not annoying, I have the feeling that if mounting was made by the use of rubber dual side pins instead of screws, the fan operation would appear as even more noiseless.
Especially if your working environment is extremely quiet (work bench).
 
I am attaching the PDF Data sheet of those fans.
What is missing from this PDF is the Fan life expectancy in MTBF.