Box for WS XS-12

I haven't been on the water yet this year, this is the last week of school and the lakes here are TRASHED. I'm thinking about passing the time by building a new sub box for the boat. Pretty sure I want to go ported and build it for a WS XS-12 even though I will use my existing sub until I have the $$ to upgrade subs and amps. Is the WS suggested box the best? Any advantage to a slot port over a tube?

Thanks

Picture just for the heck of it.