I don't use ladders above 2 storey height anymore and will only use ladders as a last resort now with safety devices fitted as in example pic. Both ladder safety devices fitted to that ladder have been independantly tested and approved by H&S unlike so say many other so called ladder safety devices you can buy that are not.
Customers are also impressed with that setup and that I take H&S seriously when using ladders especially on potentially slippery surfaces like pavers, decks etc.