Thank you very much for taking the time to contact HTC Technical Support! Congratulations on your new EVO 4G LTE! I appreciate your interest in multitasking on your new device, and I will gladly provide clarification!
HTC is aware of some questions in the enthusiast community about how the HTC EVO 4G LTE handles multitasking and memory management for background apps. We value the community's input and are always looking for ways to enhance customers' experience with our devices. That said, right now multitasking is operating normally according to our custom memory management specifications which balance core ICS features with a consistent HTC Sense experience.
In the interim, I would like you to check the following, to ensure that your developer options are set up accordingly to maximize the experience on your new device:
Please tap Settings> Developer Options and please set the Application settings to default stock settings.
The default settings are:
Don't Keep Activities is "Disabled"
Background Process Limit is set to "Standard Limit"
I hope this provides clarification