ears, the electro amps should have no problems w/wirtually *any* speaker loads, as the mfr claims they're stable down to 0.5 ohms.
re: i/c's, i haven't experimented w/any of the spendy stuff, i'm happy w/the tara labs quantum iv, which i use between pre-n-crossover, & from crossover-to-amps. these seem to me to be wery neutral, which is what i like. at some point, i may try something like alpha-core silver or silver-plated copper - perhaps i may gain even *more* resolution, but i don't wanna lose the neutral tonal balance...
to run xlr's, in a true balanced configuration, i'd have to send my marchand x-over back to have it set-up for xlr's. phil marchand sez the conwersion makes the x-over a true differential balanced unit instead of yust allowing the xlr cabling to be used in a single-ended circuit. but, he also sez that there will be no sonic benefits, even tho my pre is a true balanced design, & so are the latest electro amps. he sez the only reason ewe may get an improvement is if ya have an enwironment that creates too much noise w/single-ended cabling. i have also heard others who feel this way regarding balanced i/c's. i was interested in trying it, as the i/c between my pre & x-over is ~18', but it's wirtually silent - no noise issues in my enwironment.
re: running mono, this is something i *have* wanted to try, unfortunately my aw100 is a bit older, & doesn't allow for bridging, even tho it's supposedly the same in all other respects - this according to heinz preiss, electro's n-american service technician. this is why i had it adwertised for sale - i was trying to locate a used aw75, which *is* bridgeable, to match up w/the aw75 i have. well, unable to find one after looking for over a year, i've found a good deal on two brand-gnu aw60's, which will get tried as bridged mono-blocs (good for 220wpc), *and* they will also be tried in a vertical-biamped configuration. ironically, yust as i thought i had the aw100 sold, & after i sent the funds for the aw60's, i got a response from someone w/an aw75 that wants to trade straight-across for my aw100! he's not interested in bridging, he likes the electro sound & yust wants a bit more yuice. if this pans out, i may ackshully be able to run all four amps as monoblocs - one for each driver of my monitors! ;~) should be fun! :>)
good luck w/yer gnu amp, doug s.