Is a 1-wire alternator better than a 3-wire?

No. A traditional 1-wire (or self-exciting) alternator is simpler to wire, but a 3-wire isn’t really all that difficult at all. Traditional 1-wire alternators typically require about 1200 engine RPM for the regulator to be excited. If you get stuck at a traffic light for any length of time, a traditional 1-wire alternator will typically also un-excite when RPM is below that threshold (for even a short time at idle) causing your alternator to go into hibernation until you get underway and re-excite the regulator. A 3-wire alternator excites the moment the key is in the Ignition / Run position. In addition, some 3-wire alternators have a sense lead that can be interfaced at a power junction, like an under hood fuse panel or hot spot, so that the regulator can adjust the output voltage in unison with the demands of the vehicle accessories.