I compared both of these speakers before purchasing a pair of RM40s. IMO the RM30 is a better speaker.
The ribbon midranges and tweeters had superior resolution relative to the Gallo Reference and the bass of the RM30 was the equivalent of the Gallo in terms of depth. I also found that the bass of the RM30 was smoother (and better intergrated) than the Gallo. However, the Gallo is still an excellent speaker. Let your ear be the judge.
Good luck,
John