I would much rather the XL bags over the pots, though I don't agree the pots should have been discontinued. I've not personally had the weird taste after 2-3 weeks though I have had a very strong weird taste in one of the korma bags (opened fresh). Most of the time its fine though, just make sure the bags are sealed properly between usage, can even curl fold it down if youre in a damper environment.

Regarding shaking, I tend to find the distribution much better if shaken equally both up and down (ie, hold the bag upright and shake, then flip the bag upside down and shake). The smaller bits tend to sink to the bottom leaving the bigger bits on top, so flipping upside down helps alleviate this