Many of the posts here are people saying how much they love the 4s better than 2s. Seems kinds weird to me really. Don't get me wrong I have 2 4s in my fleet right now and I love them. I have a old OS 91 Surpass that has some serious miles on it, (25-30 gal) and it still runs great. I also have a fairly new Saito 82 which is a sweet little motor. For me though I don't like my 4 strokes any better that my 2 strokes. My other three planes are 2 strokes. I have one TT Pro 46 which in my mind is the best 46 on the market hands down. My other two planes have OS 55AX's on them. Now that is one awesome little motor. As much as I love the Pro 46 it just can't hang with the power of the 55AX. One of my 55's has a tuned pipe on it and i love the sound. A 2 stroke engine screaming by at 15k rpm sounds just as cool to me as a big 4 stroke roaring by. For me a good balance of both types of engines is best. As far as tuning goes I really do not think one is any easier than the other, they are just different. I can tune by ear on both sides but I have a tach for seeing the difference between props. I like to do alot of experimenting with props and seeing how the changes made in RPM affect both speed and transition. When it comes to experiementing with props you can't "hear" a certain RPM.