One thing I have not seen mentioned in this thread is smoothness of fabric and it's potentially negative effects. One issue with the junhashimoto underwear I recently bought is the extreme smoothness of the fabric. The fabric is so smooth that it provides far less grip than 100% ribbed cotton underwear (or even your own skin) would. This can result in your jeans more easily sliding up/down when you sit and stand. While nobody else is likely to notice, the ease of slippage is felt each time you sit down.