I love it! Did it for 3 years and I said at the time that it was the best thing I ever did. That job went ■■■■ up due to the pandemic so I went back to being away Mon - Fri for almost the last 2 years and I can honestly say that the last 2 years have been an absolute blur, I earned good money but have had no life whatsoever. Switched to 4x4 in my current job a couple of months ago and never again will I work Mon-Fri unless it’s sensible hours (ie 9-5).
I find that working 1 day less is neither here nor there but the extra 2 days off make such a difference to your life. You do get used to working weekends (sometimes nighting out on a Saturday feels pretty depressing) and it’s nice having days off in the week (can pick the kids up from school, take car to the garage, doctors/dentist etc).
If you are a day man,as Juddian says, then the downsides could possibly be if your other half works Mon-Fri or you have a busy social life that revolves around weekends. If you currently night out all week then there are no downsides really because you have no life anyway 