This was my first purchase from halo, I bought subzero, coolmist, twisted java, and the free sample of voodoo.  I filled up a new tank with subzero and vaped right away, it had a very very very strong "halls" type sensation to it.  Very very strong throat hit, very strong cooling sensation.  To be honest, it wasnt what I expected.  Its not horrible, I am still enjoying it, but I will try the other menthols to see if I like the others more.  
Off topic, but coolmist.. I'm not sure if its me or the juice (I know halo will say its me duhh) but I cant wrap my head around the flavor.  It tasted very weird and chemical like out of the bottle, let it steep for a few days and gave it a go.  It has a slight throat hit/menthol feel to it, but I cant taste any other flavors too well.  kind of confused on that one.