Walter,
It depends a lot on what type of feed line you use. If
you use coax to feed the loop, performance will probably
be about the same or worse than the dipole. If you use an
open wire or ladder line feed line through a tuner, you will
probably see ~some~ difference between the two antennas. How
much is anyone's guess. I like large loop antennas. I've
found that using ladder line and a tuner will make them usable
on more than one band and usually performs better than a dipole
used the same way (I don't have the best place to put up an
antenna to start with). Every installation is different so
what works great for me, here, may not work very well at your
location. Having said that, try the loop. If you don't like
how it performs, change back.
'Doc