I've replaced several 400W MH fixtures with 6 lamp T5's in several different businesses. Each installation to T5's improved the light (more) and resulted in less electricity (aprox 1/3 less) usage. No one has complained of any harmonics or causes any electrical problems with other adjacent tennats. Defineatly the way to go, especially if your changing out ballasts on the MH fixtures, plus you have advantage of instant on. Our price was about $215 per fixture plus 6 blubs at 6.50 each. Highly recommended.
