OP is not saying he will be cashing out. He is saying that he will roll it over into an IRA. Doesn't he have 60 days to do that without any tax consequences?
As to rate of return, 6% is not so difficult today if invested in good mutual and closed-end funds. A conservative rate today would be 5-5.5%. OP has 25 years to retirement and he can take some risks in the next 10-15 years for higher returns.
I have closed end funds that trade on NYSE that pay 12% and I'm past full retirement age.
I agree with Jack that a bird in the hand is worth two in the bush. Back in 2008, I had lots of rich clients who were cashing out annuities and taking big looses because of the uncertainty of the markets.
Personally, I would never invest in an annuity. All they do is make insurance companies and the agents rich. I can take care of my retirement investments, designate a beneficiary to the accounts, and if I die, my money is not in the hands of an insurance company.

