XYplorer (Pro) in my case, because I really like it's scripting capabilities...

I'm just missing Bandizip (http://www.bandicam.com/bandizip/) in that comparison.

Portable version, can be used in scripts and has a nice progress bar while beeing invoked from cli.

I've did a short speed comparison myself:
Source: 5795 Files, 566 folders, 1,05GB
Source and destination are on the same partition

Compress command lines:
WinRAR.exe a -afzip -r "D:\winrar_Test.zip" "D:\Test\*"
Bandizip32.exe /archive "D:\bandizip_Test.zip" "D:\Test"

Extract command lines:
WinRAR.exe x "D:\winrar_Test.zip" "D:\new_Test\"
Bandizip32.exe /extract "D:\new_Test" "D:\bandizip_Test.zip"

Packer | Extract Time | Compress Time | Compressed Size (MB)
--------------------------------------------------------
Winrar  |        18        |       58           |          870
BandiZ |        18        |       58           |          869

Not bad for a free alternative.

Can I put Mint on it as a dual boot easily?

At least you can try. Nobody knows if something will go terrible wrong ;) It's boot manager (grub) will (most likely) find your Win 7 boot record and include it in it's own. Make an image of you current installation before you go dualbooting :)