I use a cup holder , works great for morning coffee , and will hold any water bottle.

 

I used a back pack type one 2 weeks ago for the first time. I had it on my back and it forced me to lean forward for the ride. My back was killing me the next day. I strapped it in the passenger seat next time, a bungee on the passenger grab across to the luggage rack on my tour pak. The hose is long enough, and it worked really well. I did a 3 day trip of about 800 or 900 miles. I like it.
It keeps the liquid at a decent temp, once you clear the hose. I loaded it with ice chips then added water, and more chips. It stayed cool all day long. I rode about 250 miles that day, half of that at 105 degree weather, and the water was still cool the next day.
I suppose the model and insulation for that model is a consideration.

 

Get the anti-microbial Hydra-Cleaner to clean the bladder. A couple of drops will prevent your Camelback from becoming a science project.