I have both, but my Emp is the original model. If I had to do over, I'd just buy it in Epi. The reason is Epi is much lighter and holds its shape without base shaper or bag organizer. The Epi strap is adjustable too, best bag for the money.
Thank you! I am so glad to find someone who has used both bags How well does the Epi keep its shape over time? The Emp bags lose their shapes quite a bit.