I think that what 5280 has going for it is selection. Their prices are retail, maybe a touch higher in my eyes on some things, but not so bad on others. I find their ammo to be overpriced, but this may reflect the cost incurred when they have to replace what they currently have in stock.
There are lots of evil black things to look at- and many evil black accessories. I don't know of another Denver metro store that has the displayed stock that they do. They seem to always have at least 4-5 employees there, I'm always getting asked if I need help.