My 457 and 401k are through Colorado PERA which uses Voya Financial. The account funds I have access to are PERAdvantage funds, which are basically just multiple funds in one from different financial advisors (
example). They charge 0.14% as a plan administration fee on top of those funds. The cheapest funds are the Target Retirement funds with 0.12% fund fee with 0.14% plan fee. But I too have the same TD-SDBA option and I chose to go with that as I can invest in their commission free ETF's. So it's $50 a year, plus 0.06% plan admin fee on top of my 0.10% average Vanguard ETF fee. So $50 plus 0.16% isn't horrible. But they also charge a $1 per month fee per account...as in $1 per month for the 457 and $1 per month for the 401k. So it's really $62 plus 0.16% for each account. I may have more fees than you with the $1 per month and the 0.06% fee for the SDBA options. But I figure as long as I'm maxing out my contributions, it won't take long for that $62 to be less impact than a slightly higher asset based fee.
If Fidelity is the cheapest, go with that. Otherwise Voya really isn't all that bad in my opinion. They also have very good rebalancing options and easy to use account if you went with their normal Vanguard funds.
Some math with my scenario...
SDBA is 0.06% plan fee plus 0.10% ETF average fee for a total of 0.16% of assets.
On top of asset based fee, $1 per month and $50 per year for a total of $62 per year.
1st year 62/18000 = 0.34% + 0.16% = .50%
2nd year 62/36000 = 0.17% + 0.16% = .33%
3rd year 62/54000 = 0.11% + 0.16% = .27%
4th year 62/72000 = 0.09% + 0.16% = .25%
So by the 4th year, assuming no growth of investments, I have a lower overall fee than I would with the Target Retirement Funds. Plus I get to invest in the same Vanguard funds needed to match my asset allocation.