You have to think of your normal eating habits... if you usually only do Counter svc meals on the run, don't order appetizers or desserts at table service restaurants, or enjoy being more spontaneous (not being tied down by PS times, etc), the meal plan MIGHT not be a good fit for you.
Take a look at the menus on allearsnet.com and price out your normal choices. If you would spend more than $35 per day for your meals (tax and tip included), then the Dining plan is worth it. If not, then it may or may not be a good deal.
Do you want to eat at more TS restaurants as opposed to all CS? Do you want to be able to order anything on the menu, and not worry about price? Do you want to pre-pay your meals, so the cost is known? Are you okay with staying to a schedule of PS times for your TS meals? If so, give the Dining plan a try! If you don't like it, you will know not to do it in the future.