As per the title really
What are they like, any good, would you recommend, pros/cons?
It's one of these - https://securityforbikes.com/shed-shackle.php
It'd be the only anchor point for a chain but not the only security
Don't really want to cut out a bit of floor and go down the sunken concrete bucket route
Fitted one when I was still at my mums. Well made, seem strong. Decent company to deal with too.
I had one, someone managed to chew through it with bolt croppers a take 2 bikes. It must have taken a fair bit of effort and taken some time so if you have other security measures then it might be enough. I think paired with a shed alarm of some sort it would be fine.
Yep, I've got one combined with a Pragmasis 16mm chain or two 🙂
It's not been tested to destruction (thankfully) and I have other security measures as well.
I was in the same situation as you, not wanting to cut the floor, so I'm pretty happy with the job it does.