I was a Mule user for years. Tried the Kudu and didn’t like that loaded it’s huge great hump. Basically the back of the pack is a bit bigger than the protector. Two chest strap maybe a good thing, maybe a PITA. Waist strap not impressive.
I’ve got an Ergon BE2 for everyday and the Evoc Blackline for big stuff. Both are considerably more stable and very, very usable. The Ergon is naturally a storage compromise but simple if you use a keg in a bottle cage. The Evoc is well thought through in every detail – you may not agree with everything (zipped pockets vs elasicated pouches) but everything has a form and a decision.
If you like the Cambelbak way, take a look at the Endura. It’s like a Kudu but better executed.