The thing about company 401ks is that they have limited choices, those choices can change, and you have no control over when and if they do. You are at your company's mercy.
If you roll your 401ks over into traditional IRAs at whatever brokerage firm you want to use (we just moved our accounts to Vanguard, but Fidelity has some index funds similar to what we like at Vanguard), you should have far more control over what you invest in, without incurring the taxable event of transferring to a Roth IRA.
Also, if you foresee any low-income years coming up, you'd be able to transfer chunks of your traditional IRAs into Roth IRAs at a slower pace, with lower taxes. I don't think you can just transfer money out of 401ks like that.
When we moved our accounts to Vanguard, because of some timing mix-ups, we were out of the market for about 3-4 weeks. Which, in the long term, will be totally meaningless. If you think in terms of decades instead of months or years, you realize that a few days or weeks don't really matter.
Good luck.