Not too bad, but not in a true wakeboard boat's league. It's hard to maintain wakeboard speeds in an i/o when you weight them down.
You can work with weighting it a bit, and messing with the trim to try to get a good wake that doesn't wash over. The wake might be a bit wider also, making it tougher to go W2W.
Anyway, you'll definitely be able to have fun behind it... It beats the heck out of nothing!