Good speed and good engine, although I've never had the opportunity to try one.
I like the Tohatsu M18 myself, which apparently is almost the same as a Mercury 15 super. I measured 22.5 knots average (going both directions) 2-up on my 3.8m Zodiac Futura. And 20 knots 1-up with a Parsun 15 hp 4-stroke.
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