The fact that the OP has the withdrawal rate of MMIC at 4% and the annuity from the “other plan” at 6% makes me think there is definitely a hidden agenda on the OP’s part. At least it appears that way. Since the other plan is not inheritable then a fair comparison would be to give a reasonable return on the money say 8% for MMIC and draw it down to zero at some age say 85. I think that comparison would show the MMIC wildly better for almost everybody.