Yah, Maynard, I wouldn't do spoilerons or flaperons on a plane that I was IN, ever. Especially not flaperons- see Cmoulders note above. He's been a font jof good info for me!
Quoting "Flight Magazine":
"In typical business jets the thrust to weight ratio is close to 3.0 pounds of airplane for each pound of takeoff thrust. With that much thrust the Learjet .."

so that's 1:3 Thrust:Weight ratio vs the >>1:1 ratio on a model plane (like mine @6lb 13oz w/Saito91) that can climb or even pop out of a hover. More of a guided rocket in many ways. I'm guessing that your 75 still puts you at 0.8:1, a-kickin' the feathers off a Learjet!!
But it is really neat, since we lack FAA certified mechanics and fly in some incredible scale winds, that we can instantly pop the spoilerons up to shorten a floaty or otherwise problematic landing (like OOPS, I got the CG too far back!).
My engine idles at well over 2300 rpm, so with the 7 pitch prop, on approach it has 15mph+ blast coming out of it. I'm guessing my Phoenix lands at 10mph tops with no spoilerons. To just bring it down, on a runway that is NOT miles long, dumping the lift on ~20% of the wing chord sure works wonders! What's more, spoilerons give reflex and wash-out, stabilizing roll quite a bit, and making the stall more gradual in addition to speeding up the landing so that wind speed and variation are less significant vs the landing speed. To your point, I think that we (I) use spoilerons and flaperons because they are cheap and fun- no extra hingeing, no extra servos and pushrods and servo wires! I think that real flaps or spoilers would add 2-3 oz minimum, and I for one wouldn't want that. I've done a dozen or so planes in the past 15 years, and never bothered with flaps, many call the simplistic flaperon/spoileron setup a "full house" in this hobby!

PS Monday's weather looks (relatively) great for SE Michigan if you are off work.... I'm there- we're gonna light a fire and bring our radio muffs and go for it!!!