I have a year old 6 hp kawasaki engine on a toro proline and just picked up a suzuki powered one. The kawasaki is a good engine but it has bogged down for me in thick, wet turf. I think the new 6.5 hp kawasaki rated at 179 cc might help the power. The Suzuki is rated at 122 cc so it should not be as powerful as the kawasaki but being a two stroke, it should give you two strokes for each stroke a 4 cycle engine gives you. Once we start cutting here in a few weeks, I should be able to tell better. In addition, the lighter weight of the Suzuki should make for a quicker cutting unit even though both the kawasaki and Suzuki have the same speed.
How high should you put the rpms on the Suzuki? I set the kawasaki to 3600 rpm and it works great.