The well known outdoor gear manufacturer Mountain Safety Research has developed a newer, better pump water filter. It is the Guardian Purifier. This equipment garnered the 2016 Backpacker Magazine gear of the year award.
Compared with most (if not all) water filters on the market, it has many advantages, including: removes viruses; self-cleaning (no back flushing or brushing); 10,000 liters lifetime use (about 5 times the average); no removable parts; no home maintenance; screws onto the top of a Nalgene bottle or MSR dromedary bag (no special cap); and the pre-filter intake works under water or on the surface (which ever is cleaner).
But the bad news is that, compared to MSR's next best filter, the HyperFlow, the Guardian is: twice as heavy (17 ounces vs. 8 ounces); twice as big (8 inches by 5 inches vs. 7 inches by 4 inches; and 3.5 times the price ($350 vs. $100.
Conclusion: if you are going car camping and need a filter to last for decades, or to another country or equipping an expedition with a large number of persons, then choose the Guardian. But viruses are rare in the USA. For backpacking in our country, stick with the HyperFlow or other brand's similar filter.