I got one for the first time almost a year ago.
why? in all honesty.
I thought it would help me lift more, has it......maybe.
I use it for max sets only (whether that be for 1 rep or 8 reps).
I had squatted over 500lbs without a belt before getting one. I have no worries about the safety part of it as my back is strong and my form is good. I definitely feel tighter with it and I'm glad I have one.
I have an inzer single prong in orange I say spend the $100 and get one, use it for max attempts only. It's not that big of a deal, I can see how it would be easy to rely on one though, it does make you feel tighter and more stable.