Same as poster above. Sawyer squeeze. Leave bladder in my backpack, buy fittings to connect squeeze unit directly to water bladder. Fill dirty water container. Attach to filter, squeeze, reconnect bite valve. Easy. Fast.
I forgot to mention. I bought more hose so it filters a little faster. I think it comes with 2 feet. I have a 4’ piece that I use. I also have a 6’ piece (never used it) but I imagine it would be even faster. I usually just set it up where I can set my nalgene beneath it and the filter stops right inside the rim. Then I don’t do anything until I need to shut the flow off.
I’ve ran the platypus gravity for over a decade. Good system. At high elevation and later hunts you have to sleep with it but that’s every system I’m familiar with, I would never trust a filter after a freeze cycle. Small size including hoses and I’m used to so much crap in my bag what’s one more thing (phone, charger, headlamp, nalgene, no kitchen sink yet)
Platypus with quick connects to a 3l bladder. Also fill up two smart water bottles. I drink a lot of water, and sometimes finding water while covering ground is difficult. Water is always worth the weight, IMO.
When it was time to replace my Sawyer Mini after a freeze and potential compromise, I ended up with a BeFree which is a soft bottle with a screw-on filter. I like the simplicity of it a lot, and it seems to do about the same as the Sawyer Mini as far as flow rate. That little soft bottle, like most, is a bit of a pain to fill so I will probably get another CNOC threaded for the BeFree.
For early season hunts in places you have easy access to water, a Grayl would be the way to go. It's your nalgene and the filter. You could fill a dromlite/bladder by filtering 20-24 ounces at a time with the Grayl as well if you needed to carry more water.