I wanted to get a cake decorating kit for my niece who is just starting out with cake decorating, and could not decide between this set and its bigger brother, the Wilton 2109-859 (Wilton 2109-859 50-Piece Tool and Caddy Decorating Set). I went with this one since, for the money, it provided me with a better value (at the time I purchased it, this was about 1/3 the cost of the bigger set).
Both sets have many of the same items. Listed below is a run-down of the similarities and differences:
Tips 2, 3, 5, 7, 12, 16, 18, 21, 32, 67, 101, 103, 104, 225, and 352; instruction book (which is very nicely done - a great resource!), and two couplers.
Colors: this set has 5, the bigger set has 4
Bags: This set has 24 disposable 12 inch bags; the bigger set has 18 disposable 12 inch bags and one 10 inch reusable bag
Flower nail: this set has a #9 flower nail; the bigger set has a #7
Spatula: Both sets have an 8 inch spatula, but the one in the bigger set has a nicer handle.
Storage: this set has a rather flimsy tray; the bigger set has a much nicer "tool box" with a tip organizer insert
Tips: the bigger set adds tips 47 (basketweave), 133 (drop flower), 233 (multi-opening) and 2004 (2D). This set has three tips not found in the bigger set: 48 (basketweave), 129 (drop flower) and 349 (leaf). The Wilton web site is a great place to see the differences in tip types since they show both the tip and the type of output it produces.
Misc: the bigger set includes a practice board, tip brush and decorator brush
Given the differences in price, I went for this set since I was able to get much of what was in the bigger set, plus add in a box of 12 16-inch disposable bags (Wilton Disposable 16-Inch Decorating Bags, 12 Pack) and still keep it to less than half the cost of the larger set. (As a note, the 16 inch bags are worth getting regardless of the set selected, since they hold so much more than the 12 inch bags). To compensate for the lack of a good storage system in this set, I found a plastic bin for about a dollar. It's not as nice as the storage bin in the larger set, but it keeps everything organized.
The price for both these decorating sets vary a lot, so you'll want to check prices when you purchase to see what the differential is. Regardless of which set you buy, all items are of good quality - I've never been disappointed with Wilton decorating items.