While I personally haven't used it in spar, it's a very fun little shotgun to use for its high spread and low freeze combination. I used it very often while pking in the PK Arena and inside bases to break up hallway spam to clear a pathway, since the high spread enables the user to stay clear of the opponent's line of fire. I recorded a video some time ago for a demonstration while pking outside; hopefully it gives you an idea on what you can do with it either inside or outside of spar:
I think of the Sawed more of a tactical weapon to support your team, giving them more room to shoot in GST, LMS even solo, and Gang Spar.
its sawed off not just sawed.