...how can anyone justify NOT having one?
I'm just going to lob a grende into your corner when I see you poke your gun around it...
It might aid you at Vanguard, but why spend $130 on something that is a smaller version of a product that has been around for years?
Although you can see your target, it is only a limited perspective, so it may violate "blindfire" rules (possible legal liabilities) at some airsoft establishments... Unless they've grown some balls since the last time I've patronized any of them.