Personally, even though the risk is admittedly low, I'm not comfortable with a water treatment solution that won't deal with viruses. My current choice is a pre-filter with a SteriPen (boiling & MP1 tablets are my back-ups).

Even if using a full blown filter, I'd feel safer with an added step that could neutralize any viruses that may be present.

That said, there certainly are lots of people that rely solely on a filter with seemingly good results; I could just be too cautious in my thinking on this.