Yes they are very good. Brethen is a concept album based on American Indians. Nightbreaker was the first Mike Dimeo release and Brethen was his second album with the group.
I personally love all the lineups of this group. The early stuff with Speranza kicks ass and is NWOBHM before that genre existed. The Rhett Forester years was great as was the Tony Moore years, but I got into this group in 1998 so Mike Dimeo has always been my favorite. Sons of Society and Through the Storm are very underated releases, and MIke's voice on these are amazing. The cocept album Inishmore is also very good. This band is one of the most amazing but still underated bands of all time. It blows my mind how many hard rock and metal fans don't even know who this band is. Every time I ask someone if they know the band Riot their response is always - Quiet Riot??