I have an X30 and the wakeboard wake is very good with extra weight. With just factory its good but not amazing, but add another 1-2k and it gets excellent. what i like most is the wake stays clean at all speeds and lenghts, evwn when its got 2500 of ballast. ive posted quite a few pics of the wake as well as some vids here on TT. i havent ridden an X15 but was told the 30 is like a larger X15 wake.
2013 X-30, 6.0L with 2500lbs of ballast and 500 lbs of lead.