Your carriers device insurance is not the only option.
Usually the sale person will push and encourage you to purchase device insurance. All their points of why you should get insurance are valid. But for what they offer, the plans may not be the best option for you. There are companies like SquareTrade.com that offer insurance for a device for a one time fee and no monthly fees. There are a few other companies like SquareTrade.com who charge about $99 for one year and give you the same coverage if not better coverage than the carriers plan. Do the math, most carrier options will leave you paying $10-15 a month. In the long run and short term other companies may be the better deal for you. So before a salesman cons you into signing up you for their plans, do some shopping. If you decide to stick with the carrier you have two weeks to think about it after date of purchase.
What have been your device insurance experiences?
In the past, I have gone without insurance altogether and relied on my ability to buy good used phones from a wireless dealer or on eBay. However, I do have a policy through my current carrier simply because I am grandfathered in from several years ago for around $5 per month.
I have not used or paid for insurance myself in years. I never had to use the service when I was subscribed. It was always a manufacturer issue. So I figured after adding up all the monthly cost plus the deposit I could just buy a new or slightly used phone for the same price if not cheaper.