Hi sternpat,

Generally speaking, I am a fan of rolling over 401k plans into IRAs once one leaves their employer. IRAs have much greater investment flexibility and often allow for far lower expenses than 401k plans.

The main disadvantage of such a rollover would be losing the option to borrow against your 401k. Since such loans are generally inadvisable, and since there are ways to withdraw funds from IRAs with little or no penalty in the event of a financial emergency, I don't see this disadvantage as significant in most cases.