Avoid like the plague matey, I've tried a wode variety of their concentrates and there's been something wrong with all of them:
Custard - Tasted like burning plastic straight after mixing, it's been left in the bottle steeping for just over two months (more out of laziness than anything) and it still tastes like burning plastic
Vimto - Tastes like vinegar
Vannila Cola - Tastes EXACTLY like veg gravy (not even remotely joking)
Blueberry - Tastes like blackcurrent juice rather than blueberries
Jack D's - I don't even know words to describe how bad it is, I've tried mixing it with a variety of different flavours such as their R-Bull flavour (just as bad) and it's god awful
R-Bull - Isn't anything that's anywhere near the taste of red bull, tastes and smells like cat p!ss
Banoffee - Wasn't so much bad but it gave me headaches so I decided to take that as a sign to leave it well enough alone
After trying these flavours I binned all the others that I bought from them, I did email them to complain about the quality but they fobbed me off by saying it's down to 'user error' and that there's nothing wrong with their concentrates!
Beans