I’d not put a PIR in a shed personally. It’s asking for false alarms.
I’ve mentioned it before but Verisure and their ilk get a very poor rep in the trade.
(I’m sure John’s installs are great🙂).
Some of it may be sour grapes, due to taking business of traditional security companies.
I’m not in the trade anymore, I got fed up with the kit getting worse in quality, seemed like a race to the bottom.
I still see wired systems I or colleagues installed during the 90’s in use.
I can’t comment on modern wireless kit, but I used to refuse to touch it due to false alarms and pirs not waking up. I’m sure things have moved on a bit since then. Some of the new stuff sounds quite interesting.
I’d go for a local company of a decent size. Check quotes carefully for hidden ongoing costs.