I think Worn Powerstone, Hedron Archive, Thran Dynamo and Gilded Lotus are all substantially better than this card (obviously Coalition Relic is also many levels stronger). Just an unacceptable rate in both modes, and what good does indestructible do if it's a rock so bad no one would kill it? When it comes to my Manaliths, I much prefer Chromatic Lantern; when I'm drafting Artifact Ramp decks I tend to get less land fixing because I'm assembling many Mana Rocks, and Lantern allows me to more easily cast the few colored spells that are often spread across many colors (think Balance + Wildfire + Tezzeret Agent of Bolas, or Golos). Lantern is also fantastic with the best lands in the deck, Mishra's Workshop and The Tabernacle at Pendrell Vale.
I've come down a bit on this, but indestructible matters against all the green and red creatures that can kill artifacts (I will happily kill my opponent's ramp artifacts with those), and Gilded Lotus gets killed a lot, although this being three targets instead of one probably does as much work there as the indestructible.
It's also 3 artifacts for Academy reasons, as well as other things that care about that count, and it's nice that it can be both a mediocre 3 mana artifact and a pretty good 6 mana one.
I haven't been a fan of 3 for 1 mana rocks - I think Worn Powerstone/ Coalition Relic should be the baseline with 3 mana for 2.
Private Mod Note
():
Rollback Post to RevisionRollBack
I'm actively maintaining a comprehensive article to help explain to new cube players how some complex vintage level cards work in a cube environment. Vintage Cube Cards Explained
It's also 3 artifacts for Academy reasons, as well as other things that care about that count, and it's nice that it can be both a mediocre 3 mana artifact and a pretty good 6 mana one.
375 unpowered cube - https://cubecobra.com/cube/list/601ac624832cdf1039947588
Vintage Cube Cards Explained
Here are some other articles I've written about fine tuning your cube:
1. Minimum Archetype Support
2. Improving Green Archetypes
3. Improving White Archetypes
4. Matchup Analysis
5. Cube Combos (Work in Progress)
Draft my Cube - https://cubecobra.com/cube/overview/d8i