From what i have seen from a staffer on my team, (didn't like burst, shot 300 with outburst) the outburst will give you more stability in the midlane and give you a strong arcing backend. They should both give you the same backend, but the outburst will read the midlane more than the burst. Not a huge gap between these balls....
The problem with socialism is, you eventually run out of other people's money too...