This is my second water belt of this type. I got it from a Vector cereal promotion a couple of years ago. I'm pretty sure I paid less than $10. It is the same type of belt that the Running Room sells. I believe the bottle holds 600mL. The mesh pocket is big enough for me to carry a gel or two, my cell phone, my keys and some change.
Good: I find it reasonably comfortable. It doesn't move around too much, and the slanted bottle holder makes the bottle easy to grab. Mesh pocket is good for holding limited stuff.
Bad: The bottle has fallen out on me a few times, so I have never worn it during a race. The mesh pocket is not big enough for my Clif bloks when I have my other stuff in there. So, I bought a gel flask to hook onto it.
It holds 5 gels and clips onto a belt.
Good: I guess you create less waste by using a flask rather than little packets.
Bad: The gel is hard to squeeze out, the cap gets sticky, and it freezes in the winter. I find it messy, and I end up wasting a lot of gel.
I think I bought this a long time ago to use for hiking, but I have also tried using it on a long run. You can fit larger bottles in the holders (say, 700mL). Lots of space in the center pouch to hold stuff.
Good: Holds a lot.
Bad: Holds too much. It bounces and shifts around. Much better suited for hiking than running.
Holds 6 8oz (250mL) bottles, and a small pouch to carry your keys, change, etc.
Good: Holds lots of water.
Bad: I have a medium, which is supposed to be good for a 28-30" waist. I'm on the high end, and I find it tight. Particularly if I am wearing winter layers. So, if you're going to buy one, buy a size up. I wore it once for a race and it drove me nuts. I was running with Cliff, and I took it off and made him wear it! He also complained that it was tight ;) I also find that having bottles all the way around my waist gets in the way of my swinging arms.
I hate washing the bottles. Yes, they are dishwasher safe, but I'm not convinced that the dishwasher does a great job.
I bought this from Costco for about $20. It has a bladder that holds 2L of water, and a separate compartment to put other stuff in. The drinking tube feeds up through one of the shoulder straps.
Good: I think it's good for trail running, when you don't have the option of stopping somewhere to refill your bottle. Once you have the straps and belt adjusted properly, it fits quite well and doesn't move around much. I haven't had problems with leaks.
Bad: No quick access pocket for gels, etc. I tried clipping the gel flask holder on the belt, but the strap is too thin and doesn't hold it well. I find it a pain to clean the bladder and tube. It also makes your back more sweaty!
I think this belt is supposed to be used to hold your preferred music player. I bought it for $5 from the bargain bin when I was in Vancouver for the marathon. I hadn't intended on carrying water for the race, and I wanted something with a big enough pouch for my Clif bloks, Sport Beans and cell phone. So, I bought it the day before the race and *gasp* wore it for the marathon without trying it on a test run. And it was great. What a bargain for $5.
Good: The pouch lies flat on your back and does not move around. You can fit a lot of stuff in it.
Bad: It's just a pouch, not a water belt.
I also tried out my handheld Ultimate Direction bottle (picture in a previous post). I'm not sure what I think about it yet. I felt quite awkward with it as I fumbled around trying to find a comfortable grip. I held it in my right hand and it felt strange running with the extra weight, like I was unbalanced. It felt slighly better carrying it with my left hand, but my Garmin got in the way of the bottle holder. I'm willing to give it another try, though; we'll see if the handheld grows on me.
So, it looks like the simple solutions are best for me so far: the RR quick draw for training runs, provided that I can refill the bottle on longer runs, and the RR MP3 player belt for races. I'm still sort of glad that I have lots of different options for my runs, though. Everyone has different preferences. If you don't want to spend money on all these things just to find out what works for you, maybe find out what your friends have and trade gear for a day :)