So far it has been fine for me. I have been backing it up with a Steri Pen however for viruses. I am not happy with the weight of the thing though, so next year it stays home and I will add something like chlorine tabs for other issues. I am however hyper-careful.
Oh...I may try and figure out a way to fit a pre-filter. I have a new, not terribly efficient filter from a Coghlan pump system (although I do not have the pump) which might work as a pre-filter. But I am hyper careful.