Some of their stuff is ok, some of it is even quite good - especially the older genuine multicam which they no longer make.
My old day sack was solid, good zips and clips, metal D rings and the like. I’d want to see the BTP stuff before comparing.
For CFAV I’d recommend Warrior Assault Systems’ Pegasus or Predator, a 5.11 Rush 24 or the Camelbak Motherlode if you like clamshell designs.
If you prefer a larger single compartment, it has to be a Munro really, the Karrimor SF Sabre, or the issued PLCE infantry daysack (made by PRI, who make Karrimor SF - not the same stuff as Sports Direct).
I think there is a daysack addict support group thread somewhere on here too.
(One of the previous threads: Rucksack Suggestions - #2 by Baldrick)
ETA: Karrimor Predator (not to be confused with the WAS bag of same name) is basically the Sabre with molle so a bit more military looking in plain colours.