I got both. They are different beasts. These are my impressions of both which you should consider fits your style. The atheon is a full auto rifle with base of 70 shots. When fully upgraded it shoots a lot of bullets (up to 90) but low impact. It still shoots like an auto and can be fired in burst shots. Their is recoil even with stability upgrade. The void damage is nice for strikes with a heroic modifier for void damage And VoG. The high rate of fire and number of bullets make up for the low impact but it still feels weak at times. I've heard people compare it to dr nope but with void damage but of course it's not the same. Suros is initially a full auto with base of 33 shots. If you upgrade it becomes a hybrid of scout rifle and auto rifle as rate of fire drops but damage goes up. With the stagger perk it can be a beast in PVE. Like the Archon Priest mission, you can easily headshot him and keep him staggered until you reload. I like the suros because it is great for medium range and can be accurate with zoom and for close range you can unload with automatic feature. I think the suros is more versatile than atheon. Overall I like both but if I had to pick one I would go suros. It's guaranteed you get it now and hope to get atheon. If you pass on suros then you will not have a rifle and still hope to get atheon.