Tube saturator vintage (or other) for 'tube sound' emulation?

Hi All,
Has anyone ever tried/compared a ‘real’ tube amp to something like this?:

By the by, this is a VST plugin and requires a host program. Having a Mac, I attempted to use MenuBus as it is free, but it is also out of date, and did not output sound to my usb for some reason. I found that SoundSource works very well, was made by the same person, and allows for system wide eq, etc. on Mac, and while it is $40, also has a trial that would allow fellow tinkerers to check it out:

I would be really interested in hearing if those who have a tube unit find the sound signature comparable, etc.