I have been wearing Levis 501s for as long as I remember.  Also, i have been wearing the same size 30x30 since i was 19; I am now 40 :-(  The other reviews are correct in that it seems the material is thinner.  The jeans fray quicker with washes.  However, I am a believer that jeans are not meant to be washed regularly.  If I am not mistaken, even Levi Strauss recommends that their jeans are not to be washed often as it breaks down the fabric (from personal experiance; this is true).  Actually, the thinner material makes them even more comfortable.
IMHO, forget all the brand names, fads and wierd fashions, 501s fit the same, look the same  and are simply the best.  Period.