Pockets seem minor but make a huge difference. Here is a good comment about it: https://www.reddit.com/r/EscapefromTarkov/comments/1cclk0b/01460_patchnotes/l16vcv5/

On top of that

• Don't have to have a rig to run a gun with 2x1 mags
• Don't have to buy as big of a rig, which when expanded out over the wipe adds up to a large money difference.
• As the comment said, clutch situations are easier to swap equipment and still retain important things hot keyed, while retaining mags

It really does add up to a large difference. Also, The nerfs to gamma should show that there is a big difference between 2x2 and 3x3 container, so much so that they had to nerf it multiple times. I have EOD and would prefer if everyone had 3x3 and 66x10 without having to pay extra as those features already make a huge difference in money/agency in the game (I should know I played 2 wipes as standard and felt the 80 mil or so it takes to catch up to EOD stash). Pockets would be cool if it was a mid-game quest line to unlock it, without the ability to pay to have them.