The Focals are subtly better in all sorts of ways. The most important for me is that
they're less fatiguing than Genelecs while still being very revealing. The Genelec sound
is very forward and something of an acquired taste. The Focals are front ported, which
makes them much easier to place in a room - the low-end is much better behaved if they're
close to a wall or corner. The bass extends deeper and is better controlled, the transient
response is tighter, the mid-range sounds more natural.
The Genelecs aren't
bad monitors by any means, it's just that the Focals are exceptionally good.