If all you want to do is fly around the field without a lot of vertical maneuvering, then a two-stroke 60 will be fine. However, something like the Tower .75 being basically a bored out .60, you get significantly more power for less weight than the standard .60. I had a Tower .75 on my 60 size Easysport, and it was great to pull 150' diameter loops, or make a low & slow pass and accelerate up at a steep climb angle, do outta sight stall turns, etc. I have flown a friend's 60 size 4* on a Saito .91. I love the chug-chug of the Saito, and it was adequately powered, no complaints, but did not have the zip of my Tower .75. I liked my Sr Kadet with a Saito .80, and I'm sure that would be a good choice if your friend is just moving up from a high-wing trainer. Tower .75 is great value, plenty of power, and of course you don't have to fly at full throttle all the time. Only quibble on the Tower .75 is the muffler attachment screws require a snub-nosed allen wrench and half an hour to put on/take off.