Is Apache Longbow 2 still the most realistic western heli sim
 

I know there is DCS Black Shark, but am I right that there is no serious/highly realistic NATO heli attack sim (Apache, Eurocopter Tiger) since Longbow 2 ?

I haven't seen any. Looking forward to DCS: AH-1S from Belsimtek though.

There's the Gazelle module for DCS. I have it, it's a blast. Yes one might argue that it's light-attack and reconnaissance, rather than attack, but still it packs a punch and is highly manoeuvrable; complete a loop to start altitude i.e. possible from a few feet, barrel-roll same, buckets of fun.