First time with Affinity - feedback welcome

I've been playing affinity off and on for a little while now.  You're list is fairly stock and the deck itself is pretty "modular" if you'll pardon the pun. It can be tailored to any meta and has lots of boarding and maindeck options.

I've been playing the deck below for a little bit and I like it as well. The main deck spell pierce can catch people off guard and ghost fire blade is a slightly cheaper 5th and 6th cranial plating, it puts ornithopter out of bolt range which is nice.

https://deckbox.org/sets/502486

For your deck specifically, you're going bigger than i am with so many etched champion and master of etherium... with so many 3 drops you might consider an additional mana source... it may not seem like it, but I've had plenty of games were 3 mana is very difficult to get to in affinity, or there are many other things you'd rather be doing with your mana like activating nexus or equipping a plating.    Also, when i tried the master he just got removed a lot... ymmv.

the only card I'm really confused about is Dragon's Claw, for the burn match or the UR delver that's floating around? could be a meta call, but I feel like spell pierce does a fine job here... you really just need to tempo them once to slow them down and let your board take over.  if you don't win by turn 4-6 it really just gets harder after those turns.

You don't have many bad first rounds (maybe Splinter) so win that first game and hope for the best game 2/3.

You need to mulligan aggressively.

Personally I feel that Thoughtsieze is a better main board than Spell Pierce.  I takes out those pesky combo cards before they can be played or get their feet under them.  You also get to see what your opponent is playing.

Float the mana from a mox before sacing it to ravager.

Ravager is a tricky devil and there are a lot of things it can do.  Learn them well.

what he means is tap the opal for mana and leave that mana in your mana pool... it's technically correct to do it that way, but won't matter 99% of the time.

I also rarely use ravager to sack lands/other artifacts other than when swinging for lethal... imo, it's better to play it defensively to sack targets of removal and slow roll the ravager play... which is why i like spell pierce as an option main deck.  But that all depends heavily on the matchup too. so, take this paragraph with a grain of salt.

I recently switched to chalice affinity to try it out. After GP madrid it seemed okay with so many 1 mana spells going around. It kind of poo poos on my spell pierce plan though.