Last Gear Question: Backpack?

[hike2kolob]

O.K. I am all set on gear, except for a backpack. I have an old small REI pack that will work for the short narrow slots like North Wash. However, for longer wetter stuff I think I will need a new pack. I know that Shane on Climb-Utah recommends 2500-3000 in^3. I also have a grommet kit ready to go.

What packs would you recommend? Is 2500-3000 needed? I usually don't get day packs nearly this big, but I am never carrying ropes, biners and harnesses. Is sil-nylon totally out of the question?

What about this pack?

http://www.bdel.com/gear/sphynx.php

I am looking for lightweight and comfortable over bombproof. You all have been very helpful. I appreciate your expertise.

Jason (It seems everyone on this board is named Jason)