I’m sure that good caster wheels are as stable as spikes or anyhing else, but they won’t have the sonic benefits of good modern vibration draining footers that are available today. These things really make an amazing difference in making perceived cabinet noise disappear. Wheels can’t do that. I do understand that some people need to be able to roll their speakers around for one reason or another, but I’m just saying that there is a loss sonically.
That said, I make a similar compromise because I don’t use room treatments because I don’t like the way they look in my room and they would get in the way of some furniture. We all have to make our choices.