I am not sure why #21 and #22 feel it's heavy in your system ,
but in AV-TEST , the Trend Micro's performance test is pretty great ,
better than ESET and Norton !
I didn't use Trend Micro on my PC right now ,
but my friend did , and i never hear any complain from him .
I use Trend Micro before on my VM system , to test some malware and Ransomware (just for fun) ,
I set up my VM system with 2 core CPU and 4GB RAM , still works smooth .
it was very heavy in the first few days but then it got lighter but way to heavier for my liking . I tried to bear with it and then i gave up . Internet browsing was horrendously heavy .
I guess maybe because Trend Micro are trying to scan all your system and collect the information ,
to make a white list , create a copy for your system when it's normal ,
when your system had infected or attack , Trend Micro will have the way to roll back .
But indeed , Trend Micro's internet browsing is little heavy ,
I guess it's because Trend Micro will scan those internet packet .
But Trend Micro's internet protect is powerful ,
their black list is quite adequate , and update fast ,
many people testing their internet protect , Trend Micro did great at this part .
If the safety problem is more important to you ,
a little performance impact should be acceptable .