Never moved toward them in the first place.
Not sure why the trend toward bladders and tubes etc. Will skip the psycho-sexual wisecrax.
No need for tubes, probably because I hike for enoyment, not for distance, and often stop at nice spots and, among other things, pull out the water bottle to have a drink.
Have hiked with a friend who is distance conscious, and can see why the tube can be important for some (gasp!).
One problem with the bottles is that the real wide mouth Nalgene ones that are so easy to clean are quite heavy. Never noticed this until got into BPL and began weighing every item of gear. Wrote to Nalgene, begging for a lighter bottle, no luck.
Unfortunately, designed my current MYOG pack with a sleeve on each side to accept a 3.5" diameter bottle, and now cannot find anything lighter in the same dimensions with the same wide mouth. Rubbermaid makes a great wide-mouth one qt. rectangular shaped bottle in very light plastic, but it won't fit in the sleeves. Looks like I'm going to have to cut open those sleeves and sew in some bungee tape, but hate to do it to my own creation. Took a lot of care to get those sleeves to have just the right amount of snug fit to hold the bottles securely, but also allow them to slide easily in and out. But pride goeth before the fall, so I probably will do the surgery, and drop close to a quarter pound.
Also carry a very light qt. bottle formerly made by Kenyon that looks like a plastic coke bottle, but collapses into a disc only a little over 1" thick. Very cleverly designed. I use it when it is necessary to carry another quart. But when filled, carry it strapped outside the pack. Would not be keen on carrying water inside the pack in any form. Have been in a number of situations where it was safest to drop the pack down chimneys. (OK, maybe I could have lined it down with bear bag cord.)
To each their own. I like having wide mouth, easily brush-cleanable containers, especially for carrying tea and bug juice, that stand up fairly securely on rough ground and carry outside the pack. Know that some of the roll up containers are supposed to stand up, but haven't found them able to do so as well. Maybe someone at Nalgene, Rubbermaid or the competition will read this.