I have a copy of Tezla purchased very early this year that is still in its shrink wrap.
Even though many people have said they've received replacement packs (at long last), I have yet to see anyone clearly say that the boxed copies of the newest reprint have fixed the problems present in the older versions.
So: Should I just keep/open mine and go through the replacement part process (sign up on website and request a manual, then they'll send the whole pack; yes?)?
Or: Should I buy the new release and trade away my older version (since I doubt I can send it back at this point)?
Personal opinion here, but I'd say go ahead and open it and play. I played my copy of Tezla for months before the replacement pack came in and it was fine. I kept the tokens in separate piles (most of the new scenarios want you to keep the tokens separate by factions anyway) and if I wanted to incorporate the new tokens into a regular game, I would just roll a die and draw from the runt tokens on a gold or black roll, regular token pile otherwise.
Also, if you wait and determine that the new prints correct the issues, who would want your old copy?