They're slightly resonant (being hollow - they ring if you tap them, indicated vibrations from the speakers might bleed and colour the sound). It would be good to have these accompanied by some sort of rubber clamp / vibration diffuser - I'm not putting sand in them lol (potentially a new product?).
This is such a nit-pick as they're not THAT resonant, and I'm unsure if it even effects the sound, especially with iso pads. Also the platforms are a bit small for 8inch monitors, but i've made it work. You might be able to get larger platforms, I'm currently not sure, but they're easy to detach.
Besides that, they're great quality and they also look fantastic. The base is sleek yet very heavy - the stands definitely wont topple over, even with the maximum height adjustment.
I believe these are well worth the price. Especially if you can kill the resonance with something.