Gasp! Time to ditch my grandfathered unlimited data plan?

As surprising as it is to say, unlimited data is back at Verizon.

It's been six years since the nation's largest wireless carrier offered unlimited data to new customers. Existing Verizon customers were able to hold onto their plans, but the company did everything it could to get them to switch.

These poor souls gave up device upgrades and bought their new phones at full price. In 2015, Verizon raised the price of the service by $20 a month. And it prohibited customers from using the hotspot feature on their phones to share their data service with a laptop.

But now Verizon faces hefty competition from its smaller rivals T-Mobile and Sprint, which never eliminated unlimited data. It's also confronted with the potential threat from cable companies like Comcast, which will launch a wireless service that actually uses Verizon's network later this year. As a result, Verizon is doing what it can to stem customer defections. It's a pretty good deal. But is it good enough to ditch the old grandfathered plan? In this Ask Maggie I'll offer some advice.

Dear Maggie,

I've held onto my Verizon grandfathered unlimited data and now pay about $100 month. How does the new Verizon unlimited data plan compare to the grandfathered plan? I use about 20 GB a month but often hit 30 or 40 GB. Is it worth keeping my current plan since I go over the 22 GB the new plan would throttle? And does Verizon have any plans to eliminate the grandfathered plan or force us onto the new plan?

Thanks,

Grandfathered

Dear Grandfathered,

I think you may be in luck. It might be time to let go of the old grandfathered unlimited data plan. Yes, you are allowed to keep it. Verizon has no plans to force customers to switch. But you may find the perks of the new offer compelling.

The pros

Price: Verizon's new unlimited data plan, which includes unlimited talk and text messaging too, is $80 a month. If you're paying $100 a month for your old plan, you'll save $20 a month right off the bat.

Hotspot: Unless you were paying for a separate Wi-Fi hotspot plan in addition to your original unlimited data plan, you are probably not able to use your smartphone as a hotspot. Under Verizon's new unlimited data plan, you can use your smartphone as a hotspot so that you can share up to 10GB of data a month with your laptop, Wi-Fi-only tablet or any other Wi-Fi enabled device. But keep in mind, once you hit the 10GB limit for "tethering" the service for that hotspot will be slowed to 3G speeds for the remainder of the billing cycle, regardless of whether there is congestion on the network or not.

This differs from the 22GB limit you mention in your question for your smartphone. I'll explain that below in the potential "con" section.

International calling and data: Hanging on to your old plan for the last decade has meant that you've been unable to take advantage of some of Verizon's other perks, like free text messaging and calling to Canada and Mexico, as well as free texts and calls while across the border in these countries. With the new unlimited plan, you can take advantage of those perks. And you also get up to 500 MB per day of 4G LTE roaming while in Canada and Mexico. (Speeds drop down to 2G speeds after that limit is reached.)

The cons

Of course, nothing is perfect. The biggest catch is that this is not a truly unlimited data plan. As you point out in your question, the plan is limited to 22GB of data at full 4G speeds. After that limit is hit, Verizon says it will de-prioritize your traffic when the network is congested. That means that you could experience slower speeds if you're a super heavy data user.

What does this mean in practical terms? Here's the thing to remember about this policy. Traffic is only slowed when the network is congested. And it's only "de-prioritized" so long as the network in that particular location is congested. Once congestion clears up or you move to another cell site that isn't congested, data will continue as usual and you'll be back to 4G speeds.

Think of it like driving your car on the highway. If you've hit your 22GB limit for the month, it means you won't have access to the HOV lane. This means that if the highway gets backed up, you may be stuck in traffic for a bit. Sometimes it's just a temporary slowdown because someone hits the breaks, which sets off a train reaction in traffic. But if it's during rush hour, you may be slowed down a lot longer. Meanwhile, other cars in the HOV lane may whiz by you. But once the traffic clears, you'll be zooming along again.

The bottom line

What's all this mean for you? I'm a big fan of saving money. If you can save $20 a month, I say go for it. Even if you occasionally go over the 22GB limit, it doesn't mean you will get crappy service. But you will periodically experience a slowdown -- even if the stretches could be brief. The reality is that when the wireless network is congested, everyone's traffic is slowed down anyway. That's just the nature of these networks.

Ask Maggie is an advice column that answers readers' wireless and broadband questions. If you have a question, I'd love to hear from you. Please send me an e-mail at maggie dot reardon at cbs dot com. And please put "Ask Maggie" in the subject header. You can also follow me on Facebook on my Ask Maggie page.

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