I'm having the same trouble as you and I have all the top builds 100% finished with ancients.

I have IK/Rend Wastes WW and HoTA / IK

I haven't been able to get past any of the grifts above 55. The timer is moving WAY Too fast. Even tho my characters are very strong with their gear and damage.

I feel like people are using some sort of exploit to beat the timers. Maybe just canceling all Grifts until they find one with huge mob density and pylons?

The barb doesn't really have enough DPS and survivability at once to beat the timer.

The whole problem with rend build is that its weaker than HoTA but has heals. The Hota has huge crits but the problem is that it has virtually no heals. Even with life on fury spent this wont carry you into 65+ I guarantee it.

Unity and Together as one only do so much. Again . I feel the leaderboard guys are using a exploit or insider information to get ahead of everyone else. I've been really scratching my head and wondering how they're able to beat timers.

Even if your skill level as a player is good you still need DPS. Damage output and if you're failing that it doesn't matter how well you can play the timer will beat you.

The worst out of all 3 classes is the WW build IMO. The crits are the weakest and the survivability isnt there.

I had the best luck with the Rend/IK/WW build (Hybrid that is currently number one on leaderboard)

Managed to just barely beat the timer on 61 and then shit hit the fan. Mob density went down and I couldn't keep the timer running pace with the monsters I was killing.

So in closing. The fucking rift system is gamed. You either get lucky (Like winning a scratch off ticket) and get a shit ton of power and conduit pylons on your map + huge mob density . Or you get jack shit and fail the rift.

If You disagree with me I'd like to hear what your reasoning is and downvote all you want. I just wanted to share my experience with it.