Mobile carriers are going in on 'unlimited' data plans, but they're all full of red flags

In exchange for the increased data cap, the One plan will cost more than the cheapest Simple Choice plan that’s available today, which costs $50 per month for unlimited talk, text, and 2GB of data. A more appropriate comparison might be the next step up — that costs $65 per month for a fairly sizable 6GB of data with one line, and $120 per month with four.

Individually, the Simple Choice plan that already has unlimited LTE data costs $95 per month — the same as what it costs to have a One plan with the HD video add-on. A set of four currently pays $220 for unlimited data under that plan — here, they could pay $160 for SD video only (the same as a 10GB plan now), or up to $260 if they all wanted HD.

Interestingly, T-Mobile says the One plan will do away with the carrier’s Binge On program, which allows approved apps to stream 480p video over its network without counting against a user’s data allowance. It's also raised numerous net neutrality concerns.

The carrier says existing Simple Choice users will still get Binge On, Music Freedom (essentially Binge On for music), and Data Stash (which rolls over unused data per month), but One will phase them all out. Formally, at least: In effect, the One plan will make everything those initiatives were doing the norm.

Cut through the noise and the numbers, and the One plan amounts to 1) a boon for those who need tons of mobile data and are okay with 480p video, 2) a price hike for many, 3) an annoyance for hotspot users, and 4) a minor change for those who already use an unlimited plan today. It goes live on September 6.

Sprint’s “Unlimited Freedom” plan, meanwhile, gets you unlimited talk and text, “optimized streaming video, gaming, and music,” and LTE data for “most everything else.”

Much like T-Mobile, it’s technically unlimited, but the “optimized” bit means video streaming will be capped at 480p. Online gaming will max at 2 mbps (which is slow), while music streams will top out at 500 kbps (which is good). It doesn’t appear as if Sprint will offer an HD streaming option a la the One plan. It also makes no mention of tethering. The company hasn’t responded to a request for comment.

The Unlimited Freedom plan starts at $60 per month for one line. A second will cost $40 per month. You can then add up to seven more, each at $30 per month. So a family of four would pay $160.

Again, Sprint already offers an unlimited data plan today. That’s pricier — at $75 per month for the first line, and $45 per month for the second — but also doesn’t have the restrictions this new plan introduces. (Currently, a $60 monthly plan gets you 12GB of “regular” LTE data.) It’ll be available on August 19. Sprint says its existing plans will all stay intact.

AT&T’s new unlimited plan launched earlier this year. It starts at $100 per month for one user, and $40 per month for each additional line. There’s a big catch, though: You need to buy one of the company’s DirecTV or U-Verse TV subscriptions to even be eligible for it.

The carrier also says it “may slow data speeds” after 22GB of usage. That’s a ton, but again, a plan with limits isn’t technically "unlimited."

Outside of that, the carrier rearranged its more approachable “Mobile Share Advantage” plans earlier this week. Aside from adjusting its data buckets — lowering the cost of some of its higher-capacity options, but making it so its cheapest $30 data plan offers 1GB instead of 2GB — it also said that it’s eliminating overage fees.

That means you won’t be charged extra if you go over your data allowance. (Previously, you’d be charged $15 for every extra GB.) However, it also means that you’ll be stuck at 128 kbps for the rest of your bill cycle. That could work in an emergency, but it’s a glacial speed by today’s standards.

Here’s an easy one: Verizon doesn’t have an outright unlimited data plan.

When the carrier revamped its rates earlier this year, it introduced an option to waive overage fees called “Safety Mode,” but that’s only included in its more expensive plans. It, too, caps you at 128 kbps once you go over your limit. (Unless you pay another $15 just to bring it back to LTE speeds.) Anyone on a cheaper plan has to pay $5 just to get that.

The takeaway here? Mobile plans are still a mess. T-Mobile and Sprint’s latest moves may sound appealing, but any discounts are quickly countered by genuine performance handicaps. The dream of a straightforward, mildly affordable, truly unlimited data plan is still just that: a dream.