When all said and done, albeit more expensive than most other bin liners, you cannot beat buying the original Brabantia bin bags/liners for your Brabantia bin.
These liners fit perfectly in to my 30l bin. The liners come in a plastic sleeve where you can easily remove them one by one. There is a tie at the top, so as soon as you have filled the bin, you simply pull out, tie, and dispose off. As these are original liners, they are strong and I have never had one split on me. I have used Brabantia bin liners for years.
I would also recommend that you buy in bulk as you can get a far better offer and save quite a bit of money. These liners come highly recommended.