I'm not a tall guy and I like riding with a revelate design frame pack. When I do, these bottles fit perfectly underneath in my bottle cages and not protrude too much into my frame pack. Yes, I'm also using one of those bottle cage adapters that lets me mount the cages lower. I just wished there are also lower profiles frame packs out there.
The Elite Fly Bottle is my new favorite because it's made of a nice squeezable material, it has a straight shape with a large mouth that makes it easy to fill, and it's lightweight. The cap secures nicely with no leaks, the nozzle delivers fluid quickly, and the whole thing cleans up easily. I didn't know a bottle could be this good.
I bought this to check out the claims. Yes, you can save some grams. However, the plastic is very thin as expected and it can stay sucked in after taking a drink as the valve self-closes and then it doesn't fit in the cage correctly.
I wouldn't use it as a daily bottle, but I will save it for Strava hunting ,-)