I have an x30 and we have put in 1500 on top of the stock 1k and the wake is awesome. It's similar to a BU wake in that's its very clean at all speeds and rampy. I haven't rode an X25 but the people who talk about it say it has a lot of vertical kick.
When people say stock do they mean just 1k or stock 1k plus plug and play?
There are some pics and vids of my 30 wake but next summer I will have a 2013 x30!with the 6.0 and I plan to run an extra 1k for a total of 3500. I can't wait to see the wake!
2013 X-30, 6.0L with 2500lbs of ballast and 500 lbs of lead.