This obviously means a lot to you, so I took time out to do a small test.
I just done a 200mb test file using browser then IDM.
The browser took 37 seconds and IDM took 30 seconds.
Doesn't seem like a big difference, until you try to download a file like Flashpoint 9.0 (478gb) that I downloaded yesterday. IDM took hours off that download for me.
PS,
I used a stopwatch on my phone to do the test, so unless that time is "exaggerated" too , then I am going to assume that I am right so I will continue to use IDM