The Polar bottle works pretty well for road or gravel. The valve cover keeps dust and dirt out but adds a step to the hydration process. Use your teeth to remove the cover and then open the valve, drink, and then recover. On mellow gravel this is fine but on bumpy or technical terrain, it's not ideal. The good thing is the cover can be removed from the bottle. I now use the bottles for road riding mostly.
Bought it to keep the mouthpiece clean from gravel trails. A bit on the heavy side. The insulating function was not high priority for me but couldn't find a covered mouthpiece without insulation. Other option would be to wear an hydration pack.
I like the size of this water bottle. The best part of this water bottle is that you can take if fully apart for cleaning, which is very helpful when you are using mixes in your water.
