i use both. for strictly downloading nzbs, nzbdrop will suit you well. however, i prefer
sabnzb which is strictly free. i have sabnzb configured to a dropbox folder so i can drop nzbs in the folder from anywhere and since sabnzb is a service it will download it maximizing my bandwidth when i am away from my computer
the new version of unison is definitely a game changer. if you actually need to download headers it is the way to go. unison is finally catching up to its windows counterparts. i was a unison user before the upgrade and gladly paid the $20 or so for the upgrade, its that good (for me at least).
