I have them.
The pros: very sturdy: no step wobble at all when using them.
I like them also for lunges: I step forward onto the slant.
You can also stack them to make an even surface and use them under the High Step (makes it a bit sturdier)
The cons: only one angle is possible when using them for bench work, with no risers under one end and 3 under the other, plus the slanted riser.
They are rather pricey, especially now that the price has increased by $10 in most places.