Short answer: I don't like the shoulder strap water bottle mount option. I do like the old Dana Designs "wet rib" and my most common go-to these days is "L" or preferably "XL" Marsupial Gear bino chest pack.
I DO like getting heavy stuff on my chest to balance the load.
Dana Designs was sold and re-established by Mr. Dana as "Mystery Ranch".
I have an original Dana Designs "Wet Rib" which are chest pockets that leash between the shoulder straps and incorporate a large zipper storage pocket along with a water bottle sleeve sized theoretically for a one quart Nalgene. Dana's new company, Mystery Ranch, makes a design similar to the original (but not as good):
Mystery Ranch "wingman". I like the original better because the storage pocket was larger and IIRC, I could get a second bottle in the storage compartment. The storage is good for gloves, food, balaclave, pistol, etc.
I also have an ultralight product that attaches to a shoulder strap but I don't care much for it. (probably find it on that website that aggregates and sells boutique UL stuff)
I also have a variety of other external pouches, including EXO Mountain Gears water bottle caddy that attaches in the rear corner of the hip belt. That works fine, and I use it sometimes, but I prefer the weight in front of my chest...and sometimes I prefer a pistol mounted where the EXO water bottle thing would go. The EXO is a little heavy due to the stiffener material, but it would be impractical to use if that stiffener material was not incorporated to keep the opening "open" for water bottle replacement while hiking.
Generally speaking, better off using smaller 16 - 20 oz bottles in the "chest carry" devices.
The Dana / Mystery Ranch "wet ribs" are great but flop around a lot when you take the pack on and off due to the shoulder harness connection. The advantage of the "wet rib" / "wingman" is that it is quite a bit lighter than a binocular harness. Also, if you are planning to just "cruise" a long distance without taking your pack on and off then the "disadvantage" of a floppy "wet-rib" or "wingman" flopping around every time you put the pack on and off is low because you are not taking the pack off much during the day (scenario would be when going ultralight and covering ground). But if you have a very heavy pack it is a real PITA to have that sh*t swinging around every time you mount the pack. Also, I find the "wet ribs" can sometimes hang a bit low and bounce around on steep climbs. A bino harness stays put better and offers more points to attach other devices and pockets.
Generally, I just go for the bino harness these days. I only use the "wet-rib" style if I am going UL.
Another advantage of the bino chest pack is if you are going on a long scouting hike in the summer - carry water in the bino pocket until you set up camp, then switch to your binos. Or carry water and then use the bino pack for fishing gear at that mountain lake you arrived at. Only down side is more weight than a "wet-rib" type design. If I'm scouting in the summer, I usually am not super weight constrained because I am "training" anyway and don't have 10+ pounds of my hunting gear. If I"m actually out rifle hunting - then the bino pouch can do double duty. Water if I'm climbing or need extra water for some kind of temporary water haul and binos if I'm on the move where I frequently need the binos.
My "go to" for the last 5 years or so has been a size "L" marsupial gear binocular chest pack - but I recently "upsized" to an "XL"
I use the Marsupial brand with magnetic clasp (note - they are too short to close over the top of most water bottles). I'll typically carry either two of the smaller First Need's or one of those along with a hard sided water container like a 16 oz Nalgene. The only issues I have with the size "L" Marsupial bino chest pack & First Needs is that the bino pack is about an inch or two short so that a full First Need (the small size First Needs) can be a littly "tippy" as it protrudes above the top edge a bit much and there is a small risk of falling out (although that has never happened tome). One solution is to just drink some of it before you start walking again. I recently purchased the XL size Marsupial Gear chest pack for some larger binoculars and I'm hopeful that for summer backpacking I can better stack two First Needs or some other combination of bottles with better security and less protrusion over the top. But I havent tested the XL yet.
A bonus for the XL Marsupial gear chest pack is you can add a few other attachment pockets. I'll often add a cell phone size pocket on left side (for mappiing with the Garmin in-Reach mini2) or a RINO radio on the other side (for mapping or comms) or a different size pocket on the right side for my range finder. Some folks might add a holster or bear spray to the bottom of the chest pack.
