I've got thunderlord and super good advice. They are both good in their own right. Thunderlord has a slower fire rate but hits heavy and has pretty good stability. My qualm with it is its small mag and you don't carry much reserve ammo for it. It's good if you aren't missing a lot and don't waste ammo by continuing to fire after killing an enemy. I personally love heavy machine guns so I enjoy using both thunderlord and SGA. I also have corrective measure (legendary void) so I've got heavy MGs fire each element. Always be prepared!