MSR miniworks ex or Katadyn Vario?

Any reason why you want a pump filter? You will find that most on this forum use chemicals, such as Aquamira, gravity filters, or UV purifiers. I had a PUR Hiker but quit using it a few years ago.

The Sierra's are supposed to have pristine water.

I would go with the Sawyer gravity filters. You can buy just the filter element and the attach it to whatever bottle / bag water carrying solution you currently use. You can make the filter and tubing less than 100g. I think it is the lightest .2 micron filter solution.

A filter is OK when you have to filter yucky water, but not where your going.

My vote is UV, quickest, lightest, safest way to purify.

I am among the minority here on BPL that use pump filters. I use a Katadyn Hiker Pro, which I am happy with for the most part. It weighs a bit less than the two options you are interested in. If I was currently in the market for a new filter, I'd definitely check out the MSR Hyperflow. It only weighs 7.4 oz, and supposedly can achieve a 2.75 L/M flow rate.

I am admittedly prissy about the look and taste of water I drink. It all depends on the area where I'm hiking. The creeks and runs of PA usually run crystal-clear, and aren't muddy at all. I am fine with using just a Steripen with that water, as it looks and tastes great already. Hiking and paddling in the Adirondacks is a different story altogether. Water that hasn't been through a filter looks very similar to black tea, and has a slight bitterness. For that area, a filter is an essential for me.

From the photos I've seen of the Sierras, the creeks and streams seem closer to the ones I'm used to in PA – clear and with minimal floaties (however I have not been there yet, so I can't comment from experience). If this is the case, perhaps something like a Steripen might suit your needs better than a heavier filter?

Put this together with platypus hydration system and a two liter platypus and you got yourself a nice and light gravity filter.