I'm in a different area and we are in the middle - we do 7 but only over 4th year (starting after Easter of S3) and then we are 5 Highers (or mix with Nat5s in 5th)
Prior to my DC being in exam years, I was definitely an advocate of doing as many subjects as you can in order to keep subject choices open for Highers. However, the Nat5 courses are intensive. DS1 did 7 but one of his was Art so less academic (though still time demanding) and he coped well and got 6As and a C (in Art). He dropped 3 of his Nat 5 subjects though and then picked up a crash Higher to make up his 5. he is again coping well but he subjects are all Maths/numbers related.
DS2 is equally bright but more on the words side. He is struggling with 7 as he hasn't taken any lighter/practical subjects Music/Art/PE) . It's a lot with pressure of coursework to be submitted etc.
I think it's a little easier of an option to be doing 8 over the two years especially if they keep up something a little less intense or are able to focus on their strengths.
Technically 6 should be the standard but people are concerned for the academic children they are basically choosing their Highers at that point, but also for the less academic, they may decide on a change of target and find they haven't taken the subjects they need.
I think the Nat 5s outside school world are not such a big issue if you are heading to Uni based on Hs and AHs. It matters a lot more if they are looking at apprenticeships or college or jobs where they will be measured against people who've done their exams over two years and done more/wider choice and they've done 7 over 1 year or only have 6 - for me that's where the real unfairness comes in.
You potentially have 5 years before your DC has to make the choice and the world may be different then again....although obv appreciate you have to start sorting out High School now.