depending on the bellows and lens, a bellows is much more useable.
my bellows
Is a home project.
It began as a miranda bellows with a soligor 135mm F2.8 lens which was designed to mount on a bellows. (no focusing helix and the barrel was too short on its own to mount on a camera)
The lens had a defective aperture that could not be repaired.
I bought a 135mm enlarging lens with 18 blade aperture and mounted it in a T mount adaptor.
I also have a set of miranda extension tubes (also shown) that let me go way past 1:1.
What makes this user friendly is that the bellows has a second slide on it, in the middle, where you mount on a tripod. what you do is set the extension where you want it for magnification ratio (there is ascale on the bellows for this) and then you can slide the whole assembly back and fourth for close focus, and then do a fine adjust with the rack and pinion focusing.
With a macro lens to achieve the same type of control you need a macro focusing rail to mount the camera onto.
The other advantage with a bellows, of course, is that you can change the focal length by changing lenses, If I put a 50mm on this I coulf get 3:1 enlargement easily, and perhaps more.