There are five phones in my family and I also use multiple devices for review and evaluation so I have been asking for the ability to share data like we do with minutes for years. Verizon now has their Share Everything plans and AT&T has their Mobile Share plans so it looks like both of these carriers addressed my needs. T-Mobile, my primary carrier with five phone lines for the past 10 years, still doesn't believe that shared data is good for all families and that the new Verizon plans are costly, complicated, and punitive. As a long time T-Mobile customer, I wanted to take a closer look since I want what works best for my family too and thought shared data was the way to go. However, not all of us need all phones in a family plan with data and that is where T-Mobile can save you lots of money over the contract period.
Someone shared a great new comparison tool for the new Verizon and AT&T shared plans and they actually seem pretty simple to me. You pick your devices, you pick your data amount, and that's it. All lines come with unlimited text and voice calls so there are not a ton of other options. Now, where these plans fall down is for individuals where the initial cost of entry to use a smartphone has gone up considerably. The carriers are not giving away things for free and as people use voice less and less, the integration of unlimited voice is really an unnecessary "benefit" that results in higher fees to get in the game which then allows for seemingly lower priced shared data. I am on a plan with 3,000 shared minutes and the most we usually hit is 1,500 so there is no need or desire for unlimited minutes and the higher cost that this comes with.
T-Mobile is correct in stating that these new shared data plans raise the entry price for data where the lowest cost for an individual has increased $20 to $30 for most data amounts. However, the more data you purchase, the better deal you seem to get and the less worry you have about people on your plan going over the data limit. T-Mobile promotes the cost savings when you use their Value plans (took me a bit of searching to find out difference between Value and Classic), but the Value plans mean you pay FULL price for your smartphone or device rather than getting it subsidized. This can result in a $300 to $500 premium over two years, which likely still shows T-Mobile is cheaper. However, convincing people to pay full price for a phone is not that easy in the United States and even though I see the value, many do not. A benefit of the Value plan and full price phone is that you can have it on T-Mobile without the requirement for data (discussed why below).
I disagree with T-Mobile that these plans are more complicated and would argue they are actually simpler for the consumer. The only complication comes in tracking your data on all the devices you have on your account, but online tracking tools have made this quite simple. With these AT&T and Verizon shared plans, you just choose the devices and how much data you want.
I doubt people ever use as much data as they purchase so arguing about overage fees seems a bit pointless. As a smartphone geek who commutes by train a couple hours a day and uses a lot of data, I generally fall in the 2GB to 3GB monthly range. You can probably figure about 1GB-2GB will be fine for a typical smartphone user and if you see your family approaching this limit then have a talk and make them pay if they go over. I would LOVE for carriers to actually care about their customers and just automatically bump them up to the next level if they exceed their initial allotment, but we don't see them having systems in place to optimize and tailor their services for us.
I considered moving my family of five to Verizon's new plans, but right now only my wife and I really need data. My daughters get by just fine with text messaging and connecting to the Internet via WiFi when they need to. Thankfully, I am on a grandfathered plan where my girls can use my old smartphones and avoid having to subscribe to data. I understand that the Value plans on T-Mobile allow you to bring unlocked devices to their network and use them without data as well. IMHO, this is where other carriers are sticking it to families. Many people could likely get by just fine with using their smartphone on WiFi for heavy data usage, but I understand that all new smartphone purchases from other carriers require you to purchase data even if you don't want it. I'm sticking with my $195 five family plan for now and keeping my options for data in my court. I can add data to each phone, when I want to, for $20 for 2GB, but with my old plan (and the current Value Plan) it is NOT required or needed for younger folks whose parents pay the bills. T-Mobile may want to advertise this a bit more to help set them apart from the other carriers where parents feel obligated to buy data for kids. I am sure my daughters will all eventually need data as they enter college, but then its not too long after that when they will be off on their own family plans too.