The sapphire is an incredible beginner disc. It's got the understability to fly straight as a beginners first driver, but it's not so understable that it's unusable for a person as they start to get better form. For me the sapphire was the very first driver that I was ever able to hyzer flip and turnover without putting it on a crazy anhyzer. 
 

I would recommend the sapphire to anyone who is starting to get their form down a little bit and wants to move up to a distance driver and wants a disc that they can grow with for a while. 

Sapphier is hands down my favorite long Fairway Driver as a beginner. This has the ability to hold a repeatable and predictable line. Flies best for me in Opto MyDye and Gold. 

This is a great disc for beginners. The rim height is ideal for new players. It has enough glide and rim mass to get it out there and give you decent "long" throws. Distance means a lot to beginners because we get so little out of each toss. And this is great at helping give positive feedback and fine tune a beginner's max throws. 

I recommend this and the Dynamic Disc Breakout which flies a little straighter with less turn for all beginners.