Crystalline's db1 and its variants are the safest (if some of the work done here is accurate, they're actually plus), plus it has setups for its crystal projectile and skin. It's arguably his most complete variation as a result.
Aftershock is just really, really all-in on wacky setups. I'm hard-pressed to say it's outright better than metallic, but it certainly has way more potential. His dd1 and particularly EX dd1 can force some really hard to block setups and/or free recombos- if not just pressure, since them blocking the delayed low allows your f121 to connect essentially for free. His aerial variation seems like a really cheap 50/50 at first glance, but it's quite negative on block and is surprisingly easy to react to.
You seemed quite keen on metallic-- it's the variation I'm most familiar with, and it's technically speaking his most complete. It's almost two variations in one, though neither is stellar. Gold is the most zoning-oriented of any variant, but its plethora of projectiles are very slow startup and often give little reward (maybe a few extra percents of damage, or relative safety if they somehow get blocked and not avoided or interrupted). Lava stance is really the meat of this variation, with a launching bf4 and restanding db1. The advantage of the db1 in the corner is real and you can start getting away with Impostor-esque hit/throw guesses. It's really a shame you start the match in gold stance.
So the give and take is really safety and skin (crystal), hard setups (aftershock), and restand pressure and ghetto zoning (metallic). The nice thing with Tremor is that a lot of his best tools (stringwise and specialwise; EX dd4, db2 for combos, db3 overhead) are available to all variations, so you can mostly get away with playing the variation you like without feeling like you're sacrificing too much.
A or Deception?
