Federal is, generally writing, more prestigious. Again anecdotally, government lawyers seem to be happier in their jobs than are law firm associates. The work, for one. Just think who your client is. It is usually bigger-picture stuff, and it usually consumes less of one's personal life.
Benefits are usually excellent.
And the work is usually more directly connected to policy ideals of law school memories, rather than to the redistributive ones of practice. That sure sounds like a vote for Door Numbers Two, Three, or Four. It is easier to go elsewhere from a firm than vice versa. Again, a few years as an Assistant District Attorney is considered training for firms, but the effect is often circular as the more prestigious firms feed from, and feed, government offices. It boils down to what you want.