The advantage of using Ubuntu even for "power users" is the level of support available.

Since it has such a large share of the Linux desktop market it's easy to find solutions for most of your common Ubuntu problems.

I don't really want to go back to the days when everyone used a different distribution where if you had an obscure problem and used google for a solution you would come to a page describing how to fix it in another distro with a completely different package management system and where the contents of /etc were completely different.

I remember posting questions on the forums of various distributions relating to problems I was having just seeing them go unreplied to in perpetuity.