Comparison of some looping pedals

[Kevin <kwyman@gmail.com>]

Hey guys,

I've been seriously considering buying a looping pedal for a few weeks
now, though am having trouble choosing which one to buy.  I've only
used the Boss RC-20, which was so-so.  I had to really drop the boot
on it to get either switch to go, and the whole 'the first loop stays
just as loud as you add more loops' thing kinda turned me off.  Also,
it seemed that you could only overdub a loop that was the same length
as the first loop.  I'm not sure if this is common with all pedals,
but I would think this would hamper some people.  What I mean is I
can't record a 2 measure beat, than say a 4 measure bass riff, etc. 
If I loop something for 2 measures, the rest of the overdubs I put on
it will have to be 2 measures as well, right?  I'd be interested to
know which pedals do this and which don't :-)

I know Keller Williams uses a Jam Man, which I found odd because I
didn't read very many positive reviews about them.  I also found the
Line 6 DL4 to be pretty nifty.

So, my problem is which of these to buy.  Like I said, I've only tried
the RC-20, so I really can't compare them.  I don't plan to use more
than one instrument live (for now), but I may use more at
home/recording/etc.  I'd like to stay around or under $200US, but
that's just a preference.

Thanks so much for your help :-D

Kevin Wyman