When drive spins up and spins down it sounds pretty bad, but once its up and running is ok. Would recommend replacing internal drive with a SCSI2SD and keeping the original drive as a backup. Commodore4ever on youtube has some good videos on the subject.
The item "CMD HD-40 SCSI Harddrive for Commodore 64 64C 128 128D GEOS TESTED & WORKING" is in sale since Tuesday, March 3, 2020. This item is in the category "Computers/Tablets & Networking\Vintage Computing\Vintage Computers & Mainframes".
The seller is "myamigashop" and is located in Memphis, Tennessee. This item can be shipped worldwide.