What would you do?

I was offered to set up a plan with fidelity where I invest so much a month and they have one of their investors build your portfolio for you. You can adjust what % you want to invest and reinvest and different methods of investing. My question is, would you let fidelity build your portfolio for you? Would you trust what you would consider a portion of your life savings in the hands of one of these programs? They show what type of stocks they would invest in, and they give an estimate return every 5-10 years up to however long you want to invest.