Is there a valid reason to carry the extra weight of spare tire? Will roadside assistance show up with tire mounted to wheel and then change it? There is no way I could change it myself.
You never HAVE to carry a spare. ERS will take care of you eventually. If you carry an unmounted or mounted spare, the ERS mechanic will change it for you and you can be on your way. If you have neither, you will wait while the ERS locates a tire of the proper size for your vehicle. On a weekend or Holiday, this may take extra time. The choice is entirely up to you. Many have found that a spare tire has saved them time and money.