Holloway,
Both are valid techniques. Controlling airspeed with power works best on big jets (apparently - I haven't tried it yet
). Many people think that controlling airspeed with elevators works better in light aircraft, although there is a lot of scope for debate. There was recently a fairly heated thread on this subject on the Instructors forum. I read the thread with interest, and the only thing I learned from it was that both methods work, and everyone seems to swear by one or the other.
F3G, if point+power works for you, that's great, stick with it.
Holloway, if your instructor has taught you to pitch for airspeed, then do it that way. If you try doing one thing while your instructor is teaching you another you won't get anywhere.
FFF
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(PS - I tried to describe why pitch for airspeed works for light aircraft and not for jets, but I realised I don't really know enough about the subject to be confident about what I was saying. I think it's a combination of momentum, and of the jets approaching on the back of the power-curve. If you're really interested, I'm sure you'll get a good answer on the Tech Log forum!)
[Edited because FF types faster than me!
]