I did a search of this sub-forum and was surprised not to see a thread with this topic so here it is.
I got back from vacation last night to find my new Hydration pack had arrived. I was always leery of wearing one of these contraptions but since I also always struggle when I do a club ride to get a sip in I thought I would give it a try. They had an awesome sale on these so how could I loose for $20 and no shipping? I started off my ride in the AM today - since it was chilly I wore my gortex shell. After about 6 miles I took the shell off as both the day and I were warming up. I now had a place to store it - did not have to tie it around my waist. +1 for the pack. As I rode all I had to do was pull the tube off its magnetic latch and I had water, no head tilting back, no struggling to put the bottle away - it was easy and I could keep my mind on peddling and I had both hands on the bars and no sense of getting off balance. I thought it would make my back sweaty, it did not, but it was a cool day. I thought the straps would bother me and restrict my breathing, there was a little bit of that but the benefits out weighed this. I did sound like a washing machine when I got out of the saddle and climbed the hills. Since I don't drink power drinks when I ride - just water, I do not anticipate a cleaning problem. I bought a 2L version and on my 30-mile ride today I only consumed about 1/2. Over the years I have bounced about 4 bottles out of the cages, one I cut in half as it landed in my spokes (those Mavic wheels are tough). I can't believe I waited this long.