It is for sure...but remember the 'they say...' logic is probably talking about old film/35mm specs, and also likely taking into consideration portrait use indoors or studio - the longer focal lengths won't work as well there. Most portrait photogs I know or talk to agree fairly universally that a 105mm or 135mm lens on full frame is what they consider their main portrait lens for outdoor work - for getting closeup shots, head & shoulders, of people with the least distortion and most comfortable working range. So that generally puts crop body users in the 70mm to 90mm range. Of course, any lens can be a portrait lens, and it's up to the photographer to decide the lens and focal length they are most comfortable - some love a good 50mm and working close, while some model shooters I know use 300mm primes for portraits from 15-20 feet away. I have to say I find the 90mm just about right - it lets me get close enough to move my angles around and find the shadow/light cast on the face just right, and interact with the model, yet not be so close that i'm standing on their toes! That 135mm zone is just right - if I had a full frame, the Zeiss 135mm F1.8 would probably be the most gorgeous portrait lens I could imagine!