I used to play it a lot, but weirdly girls call 5 hours a day or so antisocial (and it was taking up stupid amounts of my time tbf), so now I hardly play it at all.
It can be very rewarding if you're good, and very frustrating if you're not.
It's stereotyped as being full of whining script-kiddies always using hacks etc, but if you know where to look you can soon build up a big list of quality servers with good guys in.
I don't think there's a demo though, but if you know anyone with it they may have a spare guest pass which alows full online play for a few days.