I would get neither and get the Corsair Graphite 230t as I believe it is the same price as the NZXT guardian. the Spec 01 is of horrible quality and I just don't know about the quality of the Guardian (I know very little about it). If it is between those two only, then I would go for the guardian. the Corsair Graphite will be better to build in.
But, the Fractal Design Define R4 is on sale for $20 off ($80 for the case right now), and is one of my favorite cases as it is quiet and has decent airflow (along with being great to build in)...
I would get neither and get the Corsair Graphite 230t as I believe it is the same price as the NZXT guardian. the Spec 01 is of horrible quality and I just don't know about the quality of the Guardian (I know very little about it). If it is between those two only, then I would go for the guardian. the Corsair Graphite will be better to build in.
Do you know about the cable management in that case? I haven't been able to find much besides one video of a person not even using the back to route their cables in that case.