Unless your employer will allow you to leave the funds there or to take the money over more than one tax-year, then you are correct that it will be entirely subject to taxation in the year you leave that job. Assuming that is indeed the case, then from a tax standpoint you would probably be better off investing in a long-term, buy and hold taxable account.

Thanks, Pixy. I do have to take a full distribution on termination. Unless I was hanging around for a while, and the tax deferment would make a difference to the compounding, the Plan doesn't seem worthwhile. Given I'd have unlimited choices with my after-tax cash, I think that is the way to go.