I'm sick of it. If there's one feature in this game that seriously hampers gameplay, it would be the current visibility mechanic.
Gaijin decided to "improve" the algorithm for visibility a while back. The server renders which tanks are in your FoV (field of view) and only sends data to the client of tanks that should be visible to you (according to the server). Gaijin has been doing this for a while, even before 1.65 dropped. Tanks would not render when they weren't visible for you. But since 1.65 they drastically changed the system and made it stricter. Not only do solid objects like houses, rocks or hills stop vehicles from rendering, trees can do it now as well. This makes up for really weird situations. People can be behind a single trunk and disappear, because the server deems the enemy "invisible" for you.
The same thing happens at distance. You can notice this the best on big maps like Kursk and Mozdok. Due to a LoD (low object detail. Low polygon landscape in the distance for improving performance) of the landmesh (map) you should see an enemy, while the server thinks you shouln't. This creates the suddenly appearing and disappearing tanks. In the past you would see a tank reverse on the other side of Kursk, but not anymore. Now they just suddenly disappear, and reappear when they're back. Even when a tank is driving towards you on Kursk, he might suddenly disappear for no reason. You can check the system yourself by looking around a corner with 3rd person view where you should see an enemy. The enemy will remain invisible for a short moment, and then he'll suddenly appear. The "visibility check" needs some time to process what you shouldn't and should see; a process that consumes time which could possibly ruin your victory over your opponent.
Gaijin even tried to implement a WoT-like system where visibility depended on your keen vision crew skill. This is a blatant slap in the face of the self-proclaimed "realistic tank game".
Why did Gaijin implement this system? Cheaters. Gaijin thinks the only way to stop cheaters is to stop sending data of tanks you shouldn't be able to see. It's all nice and such, but the current system just doesn't work. Without a doubt the system hurts legit players more than it hurts actual cheaters.
So what do I propose? At least revert the system as to how it was in for example 1.63. There weren't as many cases of randomly appearing vehicles as there are now. The current approach Gaijin is taking to defend the game from cheaters is not working, and I'm sure they're aware of it right now. Gaijin has been doing a very good job recently of tracking down cheaters by reports and any other possible systems. It's also very nice that players can now see on the site whether someone has been banned or not. But I think the current visibility system is really overdone and destroys any kind of long-range gameplay.