Your individual minimum speed is specific to your ‘line’ and is quoted when your order or renew service with your ISP,
FTTC is rate adaptive, that means the speed is reduced depending on the environment ( mainly line length ) , so if someone has a line that can only provide ( for example ) 40Mb , then Fibre 2 ( 80Mb ) would still only provide 40Mb , and the actual speed for Fibre 1 or 2 would be the same ( switching to F2 doesn’t magically change the line characteristics ) , so it’s not the case that anyone can say ( for example) 65Mb minimum for F2 …it doesn’t work like that, the figures to take notice of are the ones that are individual to your line , you can get an idea by using this DSL checker,
https://www.broadbandchecker.btwholesale.com/#/ADSL
The advertising authorities ( in my opinion ) confuse the matter by requiring ISP to quote the average speed all customers on a particular product get, so the adverts say Fibre 2 average 68Mb ( or whatever) , but that averages out all F2 customers , I get 80 Mb on F2 because the cab is close by, someone else could get 40Mb on F2 , our average is 60Mb , it understates my speed and overstates the other customer, imagine that over possibly millions of BT FTTC customers , the average becomes a waste of time and could mislead someone on a long line (that will only get 40Mb on F2 ) that they are being short changed when the don’t get the ‘average’ 60Mb+
