Another Prop Question

[pair of jacks]

Currently running a 14 1/2 inch x 15 pitch prop on 175 Etec- get about 5400 rmp's top end. The prop is a no-name aftermarket stainless steel and the blades have little to no sweep to them. Thinking about going to a Evinrude Rebel prop 15 3/4 inch by 15 pitch with pronounced swept blades. Have heard varied guesses on what performance will be gained or lost. Before I spring for $400 would like to hear some opinions- thanks!