I have owned both, I still own the Hovland. Unfortunayely I didn't have both preamps with the same setups so I cannot give you a fair comparison.
I wasn't real thrilled with the controls of the Mac, but everything worked fine.
Not sure at all what the previous comments are to mean, other than they appear to be a happy Jadis owner.
The Hovland doesn't have a remote if that is an issue. I really like the Hovland and have no plans of selling it. Very high quality as well.
If you already like the Mac, why not go with it, it's cheaper.