The backpacker 32 oz guyot SS bottle will fit a standard 32 oz nalgine bottle and vise versa. I know it has a tapered design and I don't think it's that top heavy, I never had a problem with it spilling. The tapered design works great in my cup holder while traveling to work as well. It does have some play with the SS cup but a bandanna may quitin it. I have a case for it and it muffles it to my satisfaction but it's all in what you want.
The reason for the backpacker bottle is:
1. 32 oz bottle with universal cap and threads
2. Fits standard pump filters to remove pesticides from the water (Carbon filter).
3. Steripen fits in there with plenty of room to kill viruses and has a 32 oz dosage feature.
4. I can use it to boil water in a emergency and is a rugged bottle.
5. Use the bottom as a signal mirror (stretching it, but can be done)
6. Water stays cooler longer in it and taste better in it.
7. Reasonable cost, great company
Bad thing is it is made in China, but it is very well built I must say.
Right click on pictures below and click view image to see entire picture. I didn't have time to shrink them.