A revocable living trust allows couples to effectively double the estate tax exemption (currently $5,000,000). If you only had a will, as opposed to a trust, which left everything to your surviving spouse, you would lose your exemption.
The trust lets you keep your exemption, which could potentially save over $1,000,000 in taxes.
For specific questions about setting up a living trust and estate taxes, please contact our Estate Planning Attorney in Los Angeles today at (818) 501-5800.
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Los Angeles Estate Planning Attorneys 
The comparison was more focused between a will that leaves everything outright to your spouse and a trust (in general, which has a plethora of options). In that sense, you would not receive the same estate tax savings as you could otherwise receive. Granted, if you set up a will that contained testamentary trust provisions, you could, but that would be utilizing a form of trust, not a simple will.