Re: please help with choice between 3 backpacks
Without knowing your applications, this is a difficult question to answer.
If you're going to be carrying loads in excess of 20 lbs regularly, then the Eberlestock X4 is the way to go. The harness system is head & shoulders better than the other packs listed. The comfort level will be night & day better...
If you're looking for a "utility" pack that allows for customization, then the Spec.OPS T.H.E. pack would get my vote. They are made in the USA, allow for a good bit of space, and are very durable. As far as "assault packs" are concerned, this one is as good or better than anything on the market as far as doing a lot of different things well.
My experience with the 5.11 Rush series of packs hasn't been entirely positive. They offer an attractive design & layout but construction quality has been suspect with a number of packs I've inspected over the last 12-18 months. Also, their pricing has jumped significantly and they no longer represent the same value from several years ago. Now, I know there are a LOT of 5.11 devotees so please don't flame me. I can only go on my experience in evaluating the latest examples & I think you can do just as good with a Condor pack as a 5.11 now, at a fraction of the price.
Just my $.02. Hope this helps & best of luck to you. If you have questions, just ask! Also, please let us know your intended applications, as it may very well lead you to an entirely different set of answers!
Ceylon
deltaoutdoorsman.com