Bi-amping vs. bridging

Good stuff for sure Al.  Thanks for the insight.  My pre/pro is the Marantz AV-7005.  It's handling the bi-amping of the Kef's at the moment, without any issues I'm aware of.  I have yet to place the ML's into the mix.  So, should I be using the Front High or Front Wide for the second channel for the tweets?

Follow up: I know that the Surround Back is commonly used, but I have surround back speakers so that option is off the table.

I appreciate the input from everyone. It sounds like I will stick to the bi-amping, especially with the 4 ohm ML's.  I have plenty of amp channels available, it should just be a matter of getting the right signals from the pre to the amp(s) from what I can gather.  What would the cons be for splitting the front L/R outputs at the preamp to provide the signal into the amp?  Is this also an impedance consideration?

I really appreciate you help, Al.  I think I am going to experiment with using the Front High outputs to use as the source signal for the tweeters.  This assumes the signal will be the same as the Front's.  It would then eliminate the potential impedance/loss issues of splitting the signal from just the Front.  I'll probably give that go tonight and post the results here for reference.

Follow up:  I tried the Front High pre-outs as the source for the tweeters on the mains, and I was disappointed.  They sounded very muted and did not present musically as I had hoped.  Now, that being said, I was using the pre in stereo mode, so I presume there was some 'non-processing' going on if you will.  When I went to the All Channels selection, they did seem to wake up and became, at least to my non-audiophile ears, much brighter and clearer.  Again, I suspect it is a processing matter, so for the time being, I have returned to splitting the front mains into 4 channels for amplification sine I prefer to listen to my music in stereo mode.

Thanks, aux.  I did use the bi-amping feature of the old Onkyo, and it sounded pretty nice, the problem is, I have Surround Backs, and that's the channel the amp uses for the second source.  The Marantz does not have a bi-amp setting that I can find in the setup anywhere (probably because it is only a pre/pro), hence the splitting of signals from there to the Rotel.  Does anyone know if the Front Height or High outputs are consistent with the Front Mains?  Or are they a portion of the signal based on the size/crossover settings?

More follow-up:  The Marantz does have bi-amping capabilities buried in the Amp Assign menu of the setup.  You must set it to 'SPKR-C'.  Unfortunately for me, anyway, it requires the use of the surround back channels.  Oh well.  Decisions, decisions. ;-)

Please excuse my posting frequency, but as you might guess I stick with stuff until the best solution is found.  From the FWIW column, the HL and HR are the solution for bi-amping, IF you realize that they are also tied to the Speaker B setting on the front of the pre/pro.  I selected A+B and viola`.  Thanks to all for your input and help.