Farming pvp is by far the fastest and easiet way to gear for hard modes even hard mode ops. like most games they totaly messed up the pve gear with the easy to farm and far superior pvp gear.
And btw, columni is not vastly better than champ pvp gear, its about the same but you would wear the columni over the champion gear for pve but the champion gear is about 10 times easier to get, do your dailies and weeklies and youll have a champ set in no time at all.
Or do 3 HM Flashpoints for 20-40mins each per day and get 3 Columni Tier pieces between 4 people for the total of 1h30-2h for 3/4 of a tier piece (1 PvP Bag requires 800 marks or ~10 games which equates to ~3hours, and then it only appears to be around 1/5 chance of getting an epic, of which you may already possess). (Although ofc there is the 10bags/week you get from your weeklies and dailies)
Id actually say getting Columni is quite a bit faster than getting PvP gear if you actually know what youre doing (although I personally have 7 PvP pieces now but only just started HM FPs in last couple days).
PvP until recently was definitely the easier way to gear but now theres much more 50s many of which are of decent skill level I expect HM FPs will become the way to gear over next few weeks.