That 'data grade power' is most likely a square wave, which is what a good deal of the inexpensive inverters create, as this is easy to do electronically. Some better ones generate a wave that is sort of like a sine wave that the normal AC service is, but it still has steps in the waveform. Somewhat harder to do electronically. If you really want to get into power re-generation, you would need an inverter that generates an actual _sine_ wave, just like your power company does. THAT is hard and expensive to do - did I mention expensive? Really, if you are concerned, find someone with an ocilloscope and distorntion analyzer, and/or a power event monitor and have them monitor your power for a day.

Chances are that your AC has the usual approximately 3% harmonic distortion, and not a lot of noise on top of it. _Generally_ the heavier a power filter is, the bigger and therefore heavier the inductors are, and that indicates filtering ability to a relatively lower frequency: down into the audio band. But the downside to this is that big inductors have resistance that can limit the amount of current available from the filter circuit.

I've probably given you way too much information that you'll never need, but I guess I'm just in a typing mood today