koffee brown,
I use both the minoura cage bottle cage mount and the two fish velcro mount. Each has its strengths.
1.) Two Fish: Positives - It can be mounted and unmounted easily and the parts that are in physical contact with your bike are either rubber or nylon strap. Negatives - If you don't have it mounted well, it can come off. In addition, you have to make sure you pull it out without alot of side to side movement or it can turn and be haning off the 'side' of the bike instead of nicely centered. Overall Impression - Once you have it set up well, it works fine. I've used mine for more than a year without too much of a problem.
2.) Minoura: Positives - It has a very secure fit that feels like a 'regular' bottle holder when you are using it. It's the closest to braze ons you will get. Negatives - the mounting system causes the bottle holder to stand out about an inch or so away from the actual frame tube.. More serious is the fact that the strap that holds the Minoura onto your bike is metal...be careful or you can scrape the paint off of your frame. Overall Impression - a very solid bottle holder that I will be keeping on my bike until I can get my LBS to put on some braze ons.
Hope this helps,
Juan