Ghost: Test have been conducted at 15 VAC between neutral and ground and no resulting damaged or operational issues was recorded. The voltage drop issue is true and will result with or without harmonics; voltage drop will be increased in the neutral due to the additional current with switch mode power supplies, resulting from the non cancellation of phase currents.
Voltage drop in the 1.5 VAC range is not uncommon depending on panel (fed from a sub panel can increase VD), type of loads, amperage of circuit, length of branch circuit, conductor size, and the equipment works adequately. I had a hospital with 7.5 between neutral and ground (not recommended) but the equipment operated without issues. Just had everyone freaked out.
Some basic literature
http://www.dranetz-bmi.com//pdf/harmonicspart1.pdf
