For most things I use some form of bus compression. Over the last 5-6 years I have gone (primarily) from a smart C2 to a Cranesong to Portico 5043
to Smart C1.
Hands down the C1 is my permanent bus comp. I have no desire to change again. It mostly sits on the same settings, I rarely look at it. When I'm finishing a mix I look over and the needles are being tickled. It does more to the mix in an effortless way than all of the others IME.
I hadn't worked on a C1 before, but heard good things (as I did with the stc8 i hated). I bought it from Vintage King simply because it was an open box and cheaper than the C2 and knew that I really didn't need the "crush" and was hoping that the lack of output transformers wasn't going to be a big deal....
I always liked the C2, but was looking to see if grass was greener on some other side. I moved to cranesong stc8 and never ever enjoyed working with it or got it. If a mastering engineer had to compress, that would probably be the stuff I would want him/her to put on. I'm compressing mostly for tone/glue/snap, not level control. It was NOT was I looking for.
Moved to portico. Liked it a lot and used it a lot, but I seemed to always fight some upper mid harshness and (to me it seemed) there was a really small sweet spot of the attack speed. Too fast and it really clamped, too slow and things got a bit pointy.
The C1 came in and I haven't had to think about it at all. I just finished a thirteen song mix on an album and it was a pleasure to work on not having to fuss with settings from song to song.
Now if money were hypothetically no object, I still think I would now choose the C1. I always remembered the C2 being a slight bit more touchy and grabby, but still very very pleasant. I've always heard the hi-fi reference as well. When I think of something as more hi-fi, i think of a lot more open top and bottom and clarity....and I don't think that the C1 is "Not hi-fi" for a second. I'm not missing any top or bottom (to my knowledge)