I'm surprised the lender is even giving you a choice....are you sure that they are?
You're going to be busy new homeowners and the convenience of having the lender be responsible is hard to beat. Money reserved for taxes and insurance needs to be put into a savings account that is government insured, and those are paying what, 1 percent? in interest. So the opportunity cost of the money out of your hands is negligible, but the failure to pay taxes or insurance on time can be very costly indeed.