Intuitive Surgical is expanding its flywheel, but investors are once again aware of the growth opportunities on offer.There are many aspects of Intuitive Surgical's (ISRG 0.88%) business to appreciate. However, as famous investor Benjamin Graham one said, a good company can be a bad investment if you pay too much for it. After a big rally in Intuitive Surgical's price following third-quarter earnings, is the stock worth buying in December?What does Intuitive Surgical do?From a big-picture perspective, Intui ...