Yes, the main difference is that gold gets 50% more points than all the other levels other than platinum.

Benefit wise, with every single level, you will get upgraded from a traditional (cheapest) to a deluxe (higher floor usually) or SPG level with free water. You will be granted a late check out. These benefits can sometimes be given to a standard SPG members as well.

In my experience, a lot of properties (particularly the popular Westins and W's) will give you a hard time about getting a late check out until 4pm. They usually try to get you leave at 2pm or 3pm unless you are a platinum. Also, when it comes down to it, because there are SO many SPG, preferred plus, corporate, and gold members out there (thanks to ameniti, AMEX platinum, etc), you really will not get much upgrades or other benefits unless you are a platinum.

I am treated 10,000 times better now as a platinum than when I was a gold.