Funtouch OS, the custom Android interface used by Vivo and iQOO, has faced criticism for issues like aggressive RAM management, limited customization options, and a less refined user experience compared to competitors like ColorOS or OxygenOS. Some users find the UI visually unappealing and the lack of features like media controls on the lockscreen frustrating. 

Here's a more detailed look at the common criticisms:

1. RAM Management: 

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• Aggressive killing of background apps:
• Users have reported that apps are closed down quickly even with ample RAM available, leading to a less fluid experience and the need to re-open apps frequently.

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• Optimized battery setting behaves like Restricted:
• The "Optimized" setting, which is intended to balance battery usage and performance, sometimes behaves like the "Restricted" setting, preventing apps from running in the background as expected.

2. Limited Customization:

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• System Launcher takes over:
• After a reboot, the system launcher can override a user's preferred third-party launcher, requiring manual intervention to switch back. 

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• Lack of control over quick settings:
• Some users find the quick settings panel to be limited in functionality, requiring them to navigate to the main settings menu to adjust common connections like Wi-Fi and Bluetooth. 

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• Green tint issue:
• Some users have reported a green tint on the display, which can be a visual annoyance. 

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• App folder size limitations:
• Some users have stated that app folder size is not configurable and is fixed at a 3x3 grid. 

3. User Experience:

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• Laggy animations and slow response:
• Some users have found the animations and overall responsiveness of the UI to be lacking. 

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• Lack of game optimization:
• Some users have reported that Funtouch OS doesn't offer optimal game performance and can lead to the device overheating. 

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• Limited customization options:
• The UI lacks the depth of customization that users find in other Android skins, such as ColorOS or OxygenOS. 

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• Green tint issue:
• Some users have reported a green tint on the display, which can be a visual annoyance. 

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• Sound issues:
• Some users have reported sound cutoffs when using 4D vibration in games. 

@NipunMarya

@RockyFTW

@sharon