I went for the Trimetals one, in their slightly uprated version (floor, ground anchor, extra locks):
https://www.trimetals.co.uk/product/protect-a-cycle/
The D-locks they supply aren't brilliant - we replaced them with van style puck locks. These completely cover the shackle, which is an obvious weak point (already exploited in Edinburgh threads passim).
Even then, the locks could be cut out easily, so the four locking points just delay the power-tool equipped thief - we only use two unless we're away from the house, relying on the ground anchor instead.
A kryptonite cable was supplied to "secure" the bikes to the ground anchor, which I replaced with the biggest chain that would go through the anchor (Almax). The current version may come with a better cable, since it's now a "Loss Prevention Board tested" cable.
I did bolt it to the ground.
It takes three adult bikes relatively comfortably, and extra fluids, etc.
The base took longer to prepare than the shed, but I wanted to ensure easy installation of the shed - any unevenness tends to twist these light metal sheds, such that the bolts and holes may prove difficult to align in assembly. But then I also started from bare earth rather than have existing hard-standing I could use!
Happy for you to take a viewing.
Robert