They were definitely worth the effort before if you were specifically going for the Mysterious Chests. Now those have been boosted in cost, it may be less worthwhile.
That being said, uniques can now drop from Helltide chests, and drop rates for non-Mysterious chests have been increased so it might be a zero-sum change.
Great game made by some devs who used to work at Halfbrick (Fruit Ninja/Jetpack Joyride fame). Highly recommend playing with an actual DJ turntable for the full fantasy. Also had a recently released VR mode.
On top of all that, https://spinsha.re/