Up to about 40 miles, I take bottles. Above I use my Camelbak 100oz classic, a fairly minimalist design. Where I ride, there's usually no place to stop & fill up and I'd rather not stop anyway. It is more comfortable without the camelbak, but using it is nothing terrible. I usually forget I have it on, even in hot weather. The camelbak also keeps liquid cooler longer than my bottles (Polar insulated) and as someone else said is easier to drink out of. I'd rather wear the camelbak than try to carry an extra bottle in my back pocket. I never tried a cage that sits behind the saddle, so that's an option, but don't know if it would fit with the seat bag under the saddle. So IMO they each have their place.