Superman was a good issue. To answer AY's question on the suit, we've no answers yet but it seemed the powers/strengths of the creature he was fighting matches or surpasses Superman's (and Kryptonian material) strength. Even Superman seemed surprised the alien's attacks were getting through his suit and his own attacks weren't having much impact.
Yep. It may be that the suit is particularly vulnerable to that type of energy, or we may find out in the next issue that it's self-healing and adaptable (ala the Borg). Regardless, I'm sure it's more likely to stay solid than the average t-shirt and jeans (which is useful if you're worried about ending up naked in the middle of a fight with a super-powered alien).