Marksman is stronger at lower lvls I think (maybe until 150 or 160 or so) but bm wins at high lvls (or with apples and stuff like that)
Marksmen are also affected by Speed Infusion, so if you have a Bucc in your party you'll be doing a lot better.
Bowmasters are wanted more for higher level boss duos because of hurricane, but are also a lot more expensive to fund Marksman thanks to the new source has a 5 sec instead of 30 second cooldown on snipe/cheaper xbows/still pretty wanted + with si mule or a bucc your on par with bowmaster. Overall pick marksman : partially bias since i have one
perfect dragon shiner cross + SI mule could almost reach BM's dps , so just go with what you find more fun to play !
Being an MM myself, I'm pretty biased. The animation for MM are infinitely more fun than BM, and hurricane isn't really THAT cool. It's just fast.
I do like snipe and hurricane as well but I still cant decide which to play ): this is such a hard decision haha