Each is slightly different but it amounts to $10,250 worth of match if you max it out and then you can hit the $66,000 limit through the mega backdoor roth.
Thus you can put ~33,000-66,000 into roth ones and only 0-33,000 into pre-tax ones whereas if the employer match got you up to the full 66,000, you could fully customize it to pre or post tax however you like.