Cyma are Ok. I have used tens of thousands of litres of their AVGAS.They used to be a bit sloppy on quantities - now metered - but I have never had any quality problems except a bit of water once. No more than a pint or so. Filter it properly whoever you get it from. I get together with a few friends and place a bigger order. We get a better price that way. He's happy to split an order into three bowsers and invoice us seperately.