Hauling... single pig? or multiple smaller individual packs.

My buddies and I are going to climb west face El Cap this summer and we are having an argument. We are trying to decide weather to spend the time hauling one huge bag after climbing every pitch OR having each of us carry a smaller backpack with our own provisions and carry it with us as we climb every pitch. 

from people with experience, what are some pros and cons of each?

if you're free climbing the west face its a single day route.  How much stuff could you possibly need? A bullet pack for the second should be enough as long as the forecast is decent. If you meant to say the west buttress that is more of a wall route and a haul bag would be the way to go.  If you're trying to go fast 1 bag would be enough for 2 climbers but it sounds like you may be more than 2 people.  If you're doing the aid route jugging and cleaning with a pack on sucks and I wouldn't recommend it.  I hope that helps but your post isn't totally clear on which route you're going to climb.

There are three of us and we are planning on doing west face in two days and taking our time along the way. Hauling sounds like the way to go.

I would either haul a tiny pig and have one of the followers wear a pack or forgo the pack and haul everything, or have both followers wear big packs. One of these options will probably work better than the others depending on the system you guys plan to use, the difficulty of the terrain, and your climbing abilities.

For free climbing with 3 people on something that isn't just an easy romp here's the system I would use:

Leader leads and follower follows like normal except the follower trails a second rope and fixes it to the anchor once they reach the belay. Climber 3 then TR solos on the fixed line while follower belays leader on the next pitch. Climber 3 reaches the belay and hauls the pig and then helps organize or decluster the belay and prepare to take off again. Obviously climber 3 is going to have the least desireable role so rotating positions once or twice a day sounds reasonable. 

Unless I'm missing something what Eli is suggesting would either require 3 ropes or you would have the 3rd climber jugging a fixed line that the haul line is hanging on.  Personally I would never jug a weighted haul line because there is no way to back it up and the tension on the line would make it hard and more likely to damage the rope.  You also wouldn't want to TR solo on a weighted line.  If the line isn't weighted than that means the bag is still docked at the anchor so I'm not sure how you would free it.  The only way to do it safely would be to have the leader lead while trailing the haul line.  when they get to the anchor they would set up the haul and then belay up the second guy.  The second would trail the third rope for the last climber, but someone would need to haul, presumably the third climber when the get to the anchor.  The wall style way to do it is to have the second and third climber jug the fixed lead line but then the leader is the only one free climbing.

On a side note the west face isn't very well suited to being a multi day climb.  Any other parties will be justifiably annoyed and in your case it will probably be a lot more fun to just sleep  at the base and do it in a day.  If you want to bivouac do a short wall like the leaning tower or the column. Thats just my 2 cents

Yes, you are correct. You would have to make a decision between TR soloing or jugging on the haul line or bringing an extra rope based on what you are comfortable with.

And yes, if you're doing a bivy on a route that is usually done in a day then you're going to piss people off and that's not cool. If you absolutely must do it, then you should do it in the off season so you aren't pissing off as many people. Better yet, pick another route.

haul

Yep, haul. Have a couple of rope bags to stuff ropes in because you're going to have 3 ropes going on and it will be a mess. Good haul ropes at https://redcanyonropes.com

I can't imagine an El Cap route that would be worse to haul. It's going to be a nightmare from start to finish. 

The West Face of El Cap is a highly sought, long, in a day, free climb. You're going to piss off a ton of people. I highly recommend finding another route.