Capture One works smooth. No matters how big the catalogue is, well I only use such with up to 10'000 pics.
On the one hand you say "No matter how big" then you say your catalogs are no bigger than 10,000.
10,000 may be C1's limit.
In my personal experience, when creating a catalog, 15,000 is where C1 hit the wall as far as import speed. So 10,000 would probably be more responsive.
Well my catalog is over 3X that size and I'm here to tell ya, it ain't smooth.
Its better than 8, but still not as smooth as Media Pro or LR.
I'm talking particularly about keywords, searching, and the like. Other than that, its fine.
I'd like to see how your machine responds to a 40,000 catalog of mixed media files. By that I mean Nikon,Canon,Tiff,Raw etc.
Had I known that my increase in hardware wouldn't have made that much a difference, I could have saved the scratch(and space), bought a RAID and hooked it up to the Mini. I probably wouldn't have as I had the discretionary funds at the time, and I do like my Mac Pro.
This guy may not have such discretionary spending.