My coworker at an old job did exactly that: found a matching Vanguard fund with nearly identical funds to our 401K. It had 1/6th the fees and that company lost a significant amount of my money. The tax benefits of the higher tax free cap for 401K's versus just having an IRA were definitely not made up for by how poorly my 401K's investments went.
tl;dr: open an IRA, buy Vanguard