Last month I bought a 40oz Klean Kanteen bottle and a 33oz Sigg bottle. In the end I prefer the Klean Kanteen.

Both bottles are very light and look good. The Sigg is lighter, but not so much to really matter. Sigg wins easily in the looks department with different artwork to choose from and the bottle I have has a nice textured powder coat finish compared to the KK basic look and smooth surface.

Sigg uses an epoxy to protect your water from the aluminum and tells you not to use the bottle for long term storage. Could be a bit worrisome not knowing what's in the epoxy and the possibility of aluminum contamination. I have not noticed a metallic taste from either bottle drinking straight unfiltered tap water. I prefer the stainless steel of the KK just because it's probably on the safer side.

The bottles are both lightweight and made of thin metal. I haven't dented either but I have been very careful with them. Both feel like they would dent quite... Read more

I purchased one of these for myself after researching the problems with polycarbonate bottles. At the same time I bought SIGG bottles for my kids because they had cool designs on them. Both brands of bottles are great and much safer than the polycarbonates. I like the Klean Kanteen much better than the SIGG for the simple reason that I can put standard ice cubes in it. I have yet to find an ice cube tray that is easy to use that will fit the smaller mouth of the SIGG.

With the Klean Kanteen I get clean water and no taste of metal or plastic or anything other than water. I fill this 27 ounce bottle 3 times during the day to make sure I get enough water. I like the sports cap, because I don't have to take off a cap and lay it down somewhere. I originally bought the bottle with a poly loop cap, but when I am teaching there is never a germ-free spot to set that lid down. So I bought a sport cap, and it is very easy to drink from.

If you buy the 27 ounce Klean... Read more

After reading recent information about Sigg not sharing info about chemicals used to line the interior of their bottle, we opted to switch to Kleen Kanteen for the stainless steel. There are pros & cons:
1) obvious pro - the materials are known to be safe
2) the bottles sweat where as the Sigg did not sweat at all
3) the mouth of the bottle is large enough for ice cubes but makes it a bit more difficult to drink out of -- kind of like drinking out of a 1qt gatorade bottle --- sometimes a little bit dribbles out.
4) My 18month old loves his bottle because its the same color (stainless steel) as his dad's. We got him the sport top instead of the sippy top - and he manages just fine.
5) the slim shape fits nicely in most cup holders and water bottle carriers