Is 401K good for L visa (3/5 yrs assigment) ? (San Francisco)

I don't have a green card, might or not apply for one in the future. Expect to be in the USA Protected content . Company 401K is good Protected content % match) but not sure of implications if I take money early as I understand taxes are only deferred (really not tax free) and there are penalties for early withdraw (10%?) ... additional to the taxes that my own country (Mexico) might impose to taking the money there afterward. All comments and ideas welcomed !