There has been a bit of a chatter. The only problem is one guild holding all the power doesn't inspire others to challenge them. (not even sure in what yet)
I'm not sure how it will play out as you can increase the size of the guild with more DEC and considering these players earn the bulk of DEC just in normal play, they'll continue to grow faster than the rest.
Just an observation (no hate)

I'm just happy to get a small DEC bonus in my guild and it costs me nothing, so definitely worth it.