My only real comparison is with the NZ system (a loooooong time ago
): I was 13 when we went, had to jump ahead 6 months with the change in hemisphere but coped. Spent 2 years there and came back when I was 15, 6 months before my O Grades. Technically I jumped back 6 months to my original year, but I still had to catch up 
I ended up studying Hamlet for 3 years, as we'd done it in NZ, came back and they were over half way through Macbeth for the O Grade, so I just revised Hamlet again (cut down my choice of questions as I had to answer the generic Shakespeare question but I was ok with that) and then studied Hamlet again with the class in S5 for my Higher
. Had to do a crash Latin O Grade, as I didn't have time to study German before the Oral.
In comparison with Americans and English at Uni (went to St Andrews, where there were lots of both
), the Scots performed well. But again, that was a looooong time ago 
The Scottish education is broader than the English one, which I like. 5 Highers (for academic kids) are the norm, taken in S5 (I did 6, but that seems to be rare these days), which is the equivalent of Y12. You can then go to Uni or stay on for S6 and do Advanced Highers, more Highers (some people, for example, do a "crash" Higher in the 3rd Science, if they only did 2 Sciences in S5), or even A Levels - or re-sit any Highers for which you didn't get a good enough result.
The new Curriculum for Excellence is still bedding in. You'll get mixed views on Mumsnet as to its effect on the quality of education in Scotland but so far my experience, vicariously through my ds, who is starting S4 (and will be sitting 8 National 5s the equivalent of GCSEs in May next year), has been good. That may also be due to the pragmatic way his (state) school has been implementing it 
I can wax lyrical about the benefits of Glasgow. I love the city, its culture, its people, the architecture, its compact size and shape meaning that the beautiful countryside is easily accessible wherever you stay. We're in leafy Pollokshields on the Southside of Glasgow - easy access to the airport, one of the original 19th century planned suburbs - yet only minutes from the city centre) 