The first thing is to ask the density. 100gms/litre is the standard.
Next is wall thickness, I am not happy unless there is 40mm all round.
Are mice engineered out? The entrance should not allow mice in. Some do so beware.
The roof should have sides that keep the roof on reasonably well. A brick on top is normal.
Some have a lipped design. No use to me, and a friend who went that route is now regretting it as the wasps have bored through and it’s not looking too clever.
Is the proposed purchase compatible with your equipment? Think hard on this one.
What is the availability like?
What do I use? Swienty. It suits me for the above reasons.
Your money your choice, dinna waste it. 🙂