Micron level depends greatly on the beta ratio of the filter when comparing performance. The beta ratio is the efficiency of the filter. Example a nominal filter will have a beta ratio of 2 at a given particulate size. This means that it will only trap half of the particles above the micron rating. The higher the beta ratio, the higher percentage you will trap, but the pressure drop and price usually also go up. I can show you the calculations if you'd like.
If a single pass, you'd want a higher ratio. If on a kidney loop you can afford a lower ratio since you'll have multiple passes to filter it out.
So a higher micro level may not be a better filter. Need more info