This surely is something for VCash. With regards to Zero confirmations creating fast transaction, aren't other altcoins having an instant transfer as well.
The only one iam aware of is Dash, but that requires a higher fee to use, while xvc's is the standard fee and through xvc's ZT txes, coins are respendable faster..
There might be other differences as well, but i have never really looked into Dash to be honest.