In my SI X2 Clearo, I've got SI's 555. I think my clearo is dying as it all tastes slightly burned and the vape production isn't there like it used to be. I'll switch out to different flavor cartos too. Mostly 555 or a blank carto I filled with VaporGod's Arctic Wolf.
In my "MySmokelessDeluxe" (my first cig-a-like I got at the mall) I'm refilling a menthol carto with a mix of 555 and Arctic Wolf.
Just received in the mail a bottle of Mister-E-Liquid's Kamel Hump with extra menthol added. Have not tried it yet.