Nothing wrong with it given 25+ years to retire, a touch conservative for my tastes, but you know your risk tolerance. It's also more domestic than I think most would recommend, if you're going to be 75% equity, many mainstream recommendations would put you into 50% domestic, 25% foreign. Vanguard has tax managed international funds which may be helpful for you (I own same).
But there is no right answer. Your portfolio is only mildly aggressive and US focused, that may be exactly as you want it.
No one agrees with other people's opinions; they merely agree with their own opinions -- expressed by somebody else. Sydney Tremayne
Retired Jun 2011 at age 57
Target AA: 40% equity funds / 35% bond funds / 25% cash
Target WR: Approx 2.5% Approx 20% SI (secure income, SS only)