Edit: I've done the same process every couple years since 2013 (Mountain Lion, Mavericks and High Sierra).
I just replaced the hard drive of my mbp and decided to do a clean install of Mountain Lion (10.8.5) since I was still using Snow Leopard (10.6.8).
I kinda regret for not using Boxen to automate the process, but TBH I have this laptop for almost 3yrs and this is the first