The first thing I notice is that this is definitely a western style bit, I don't think this bit would do well with the constant contact you could get with a snaffle while riding English. It definitely isn't the most horrific bit I have seen but it isn't the lightest thing I have seen either. I would assume that the ring makes it gentler on the horse than a cracker snaffle and could discourage them from leaning on the bit. One small detail I cannot accurately judge from the picture is the screwing marks on the bit, if the bit is sharp then I would not use it. All in all, certainly nothing I would choose for my own horse but I wouldn't mind using it on a horse that is already used to this kind of bit and enjoys it.
"The trouble with the world is that the stupid are certain and the intelligent are full of doubt"