I play it since launch and it is not laggy (if it becomes laggy just change server). It had some connection problems at first but nothing too bad, you just had to retry once or twice.
The major problems players complained were not enough helicopters spawn use to “fast travel” around the map (leading to queues of people waiting for an airlift or just walking to destination) and some AI having god sight and shooting you in bushes.
There’s been several updates and the roadmap is public.
I enjoy the game but I play very slowly, I still haven’t unlocked everything. The missions are nice, I like walking in the nature to enjoy the scenery and snipe people.
I like that it is PVE or PVPVE. Other players are usually helpful and talks on the proximity chat (at least on pve) so you can be a lone wolf and participate in a more difficult assault with randoms passing by.
I’d say look at some YouTube reviews but be aware, some of those players finished the game in 48 hours and are complaining that they have nothing left to do (duh) so they want updates (which are coming).
If I hadn’t already I would definitely buy the game, maybe not on full price.