Bringing this up again, as I have found a couple more decent brands of canister:
Taylor and Brown.
These were an eBay search after I got annoyed at Coleman going from £20 for a 6pack to over £30. They were priced at £21.99 including carriage. Admittedly I have not used them carp fishing, but I think cold, wet, windy days and nights under a Beach Buddy or umbrella while pike or sea fishing might be a serious test. The canisters ran until empty with only a little reduction in flame due to low pressure.
This one was a surprise to me, NGT canisters! My mate Will mentioned them last summer after we had sworn at the Coleman canisters together previously. He picked up a bargain through Ebay and again, pike fishing mornings were the test. While I have not seen the canister run low, Will praised them for not being a problem when low.