I played the mod for years and have the standalone as well.
I really enjoyed the standalone, I think during the first three weeks it was out I played some 200 hours, but I havnt played that much recently because I leave my gaming computer at home while I'm at school. Honestly how fun the game is depends largely on who you play it with, by yourself its a decent game, but with a good group of friends or a clan it's an awesome game.
I remember times where my clan would do raids in Electro and try to hold the city for as long as possible, the firefights that ensued were a blast. Same with loot raids on the NWAF and Biota(?). On one server we played they had an Anti-KOS taskfroce that would go around the map and kill people who were raiding or camping (the thing was organised through reddit). So we raided Electro with five guys and KOS'd everything until eventually the task force showed up and absolute fun ensued, an all out war in Electro. M4's popping off on full auto, bullet impacts fucking everywhere while your sprinting through the street to keep from being flanked, snipers on the hill and counter snipers in the city, blasting a fully geared dude with my mosin in a hallway fight, then dying, coming back and killing two guys looting my corpse with a splitting axe before reclaiming my gear and bouncing.
Honestly, find a good group of people to play with and it's an amazing game.
That said the list of things that piss me off about it is also pretty long.