I've had both...and moved them both on as neither suited me.
The Sabrecat has a lot of capacity...too much IMHO to be fastened around the waist with no yoke. It just wasn't comfy for me to carry for any length of time.
The Sitka, I quite liked this when I got it, but after a while found that a single shoulder carry gave me back ache if I carried it all day.
Like all Maxpedition gear, both are well made...they just didn't suit me and my style of carrying kit.
Simon