A build that can clear Glad Crucible 150 (the loot at 170 is only marginally better) and/or SR60 is absolutely viable for endgame and gearing up.
In terms of cutting edge clear times, a glad 170 clear in the 6:00 to 7:30 range in the hands of a skilled player is very reasonable. Anything below 10 minutes for an average player is great. Anything outside of that needs to be looked at.
That will vary of course with what sort of build it is (a very safe build should not be clearing as fast as a glass cannon, likewise an AoE heavy build should do better than a single-target build in the Crucible).