Sigg bottles quite often get a bad press for things like easy denting and leaving a soured taste after having anything other than water in them. However, they are the best aluminium bottles you can buy.
Firstly don't worry about dents. They're a bit like Land Rover Defenders. They need to be a bit chipped and dented to make them look like they're used for something other than display.
Secondly, the bad soured taste only comes from putting things like milk into them. Milk doesn't usually go well with aluminium and is best put in plastic. Use them for water and they're so good at keeping it cool. Never had any problems with the metal tainting the water.
All in all, a top quality water bottle.