I take it you mean either the YAS62 (alto) or the YTS63 (tenor)? Most people learn on alto, but at 21 with clarinet and saxophone experience, the tenor is also a realistic choice.
A Yamaha sax is never a bad buy. I have a 475 alto which is the one below the 62, the 475 being upper student and 62 graduating from upper student through to pro. They are well made and consistent in tone, and hold their value well should the player decide to upgrade or (please, no!) give up.
Other makes to look out for, depending on the size of your bank balance are Selmer (the French made ones, not the American), Yanagisawa and Trevor James. There's also the Cannonball brand - fairly new and receiving mixed reviews, but a young friend of mine plays one (very well) and is more than pleased with it. Jupiter is also a good student make, but cheaper and don't hold their value so well.
A good website/shop for loads of information and a wide range of saxes is
http://www.saxophones.co.uk/