Thanks both. I'll leave everything as it is for now, fingers cross it stays stable at 8Mbps.
Another question though, previously I've switched on QoS features including apps analysis, network monitor and also firewall features. These are all left off by default for now. Will turning these on affect stability (i.e cause disconnects?)
Are you on a mission to destroy your line profile? You've said you're regularly rebooting despite knowing you're in the line training period and being repeatedly advised not to, even after that you've had another go and now swapped over to a modem/router with numerous documented issues that can cause your profile to lower. This is page 100 of the thread, it's only *just* starting to show signs it may improve since 2014.