Is there any obvious advantage for monoblocks?

monoblock offers you better control. you will have good quality bass. But this may be in the expense of good quality high and mid.

Shorter speaker cable runs too!

the myth of channel separation is just that...but they look way cool.

High power capability, that you can still pick up and carry.
Short speaker wires/long interconnects... probably a wash.
Separation (low crosstalk) is a myth unless your stereo amp is a clunker.

Staging will be a plus with mono-blocs. Separate electrical ground plane. And with the correct coupling platform under them an enhanced mechanical ground to earth. They will then react as two separate amplifiers tied together only thru the same ac outlet and the stereo source. Of course you could have several dedicated ac lines with isolated grounds. That set up makes all better. Tom