I own one and use it with my Grundig YB-400PE. I think it does a good
job, but usually only on the signals that are somewhat strong to begin
with. I live in a very electrically noisy apartment building, and I
find it enhances the listenability of signals that are already coming
in somewhat decently. I don't think it does a good job on SSB or DX
signals. If I had the ability, I would run a wire outside. I think that
would give you a much more listenable signal, as the AN-LP1 tends to
amplify RF noise quite a bit. I'm not sure what receiver you have, so
your results could be different from mine.

I hope I don't sound like I'm bashing the Sony...I think it is superior
to a simple indoor reel antenna (the kind that comes with most
portables). But it does have its limitations. If you listen to
primarily programs being beamed to the US (or wherever you live), then
the Sony will probably do a good job.