I personally dont use multiple styles.. I prefer the idea of brand recognition and my forum colors and logo are the brand.. With that maintaining multiple themes is troublesome and just adds workload. I know one style will never please everyone so maintaining multiple styles could be considered a plus for some members who say prefer dark skins over default light.. Also (and i have no experience here) ive heard that multiple styles comes with a performance degradation. I myself have no intention of ever maintaining more then one style per domain, but the subject does interest me, especially since my latest community utilizes a professional style UI.X and ive found upgrading these things a nightmare without adding Parents, Aunts and Uncle styles.. Will probably move away from that in the future and move back to a modified default skin..
So my question to those who use multiple themes, Why???
It's impossible to please everyone, providing some options seemed like a good idea. The only difference in performance that I've noticed is it takes a little longer to process when adding or removing an addon. Nothing that members would notice.
Pros: Members love it.
Cons: More work to keep them all updated. Although its not a huge deal as they're all roughly based off the same style.