I'm not exactly a "Sunday Flier Type." I can't really say who would and who wouldn't notice the change. This is a similar question to asking if a Sunday flier notices the differance between high/low wing loadings on the same plane, or higher nitro fuel, or high precision servor, etc. Anyone that is paying attention to how thier plane behaves should notice all of these changes, be it Chip Hyde or the average Sunday Pilot. A better question would be "Is the performance between 2-blade vs. 3-blade props significant enough for a Sunday Flier to worry about." To that I'd say no. There are differances between the props, and you will (should) notice the change, but the differance isn't enough to make/break the flight capability of a typical Sunday RC plane.

Yep4: What depends on pitch & weight?