The 25BB on the ARF Streak will really get it moving. A friend has one with an FP25 that runs 75 MPH which is about a 3.5 second lap on 60 foot lines. Of course a lot a flyers like their Streaks fast and that is the way many were flown in the past. I've got an old Enya 19 on mine and it's getting a 4.4 second lap on 55 foot lines which is plenty fast for me. I did have to add a trim tab to the outbaord wing to get it grooving level but it flies great now. Mine ended up about 23 ounces with no landing gear used.