I have used the NXT spray wax and find it to be a good value; easy to apply and provides a nice shine after a wash.
I think our experts will probably say that the paste will provide a bit more depth of shine, and perhaps longer lasting, so it's a trade off, but personally I like the spray.
But it's also good to note that wax is not a true "sealant," if a sealant is your goal then a different category of products should be considered
