IPad vs. iPad: Which 4G tablet should you choose?

Updated. 3G and 4G tablets haven’t exactly been hot sellers since their introduction two years ago. Driven by the big markup for the extra radios as well as the cost of the mobile data plans, customers are gravitating to Wi-Fi-only iPads and Android tablets.(s aapl)(s goog) Still, some of you may find the combination of LTE and iOS irresistible and have the pocketbook to afford it. But which iPad to buy, Verizon’s(s vz)(s vod) or AT&T’s(s t)? Here’s a quick primer on the differences between the two.

Speed: a tie, unless you live in Chicago or L.A.

In most cities, Verizon and AT&T’s network will be able to match each other megabit per megabit, and AT&T may have a slight advantage given that its LTE networks are still relatively free of customers. But in some markets AT&T’s 4G networks are a bit undersized, as they are limited to only 10 MHz of frequency bandwidth, while in other AT&T cities — and all of Verizon’s – the networks pack a full 20 MHz.

Speed tests from a Verizon LTE phone in NYC

GigaOM contributor and spectrum policy wonk Andrew Shepherd crunched some license data and found that AT&T has only 10 MHz in Chicago; Los Angeles; Oklahoma City; Charlotte, N.C.; Raleigh-Durham, N.C.; Chapel Hill, N.C.; and San Juan, Puerto Rico. Simply put, in those markets Verizon’s networks will be twice as fast.

That said, even AT&T’s pint-sized LTE networks are impressive. In a recent drive test in Chicago, AT&T was averaging 10 Mbps down and 6 Mbps up even on the highway and peaking at 20 Mbps while stationary, which should be more than enough to support any application on the iPad. But speed freaks take note: GigaOM readers have recorded Verizon 4G connections well over 60 Mbps in New York.

As for fallback networks, AT&T has Verizon beat, though don’t let the iPad’s shiny 21 Mbps and 42 Mbps HSPA+ specs fool you: AT&T’s HSPA service maxes out at 14.4 Mbps. That’s still more than four times faster than Verizon’s EV-DO, but then again, with Verizon’s network you won’t be falling back on 3G that often.

Coverage: point goes to Verizon

When the iPad goes on sale on Friday, it will have LTE covering more than 200 million people in every single major market and many of the smaller ones as well. By the year’s end, Verizon plans to cover 260 million people, leaving it only 30 million short of its covering its entire footprint.

AT&T's LTE markets are marked by the orange dots.

AT&T was late out of the gate, and as of its last estimates, it had 74 million people covered in 28 cities, though it is adding a bunch more in the coming months. Its end-of-year target is a footprint covering about half of the U.S. population.

It’s also important to note that while AT&T left some pretty big coverage gaps in its cities at launch, it appears to be rapidly filling them in. For instance, much of Chicago’s south side was without LTE when it first came online last year, but big chunks of it are now covered. The same goes for the Bay Area. Still, it’s a good idea to take a close look at both operators’ market-by-market coverage maps before you buy. You can find Verizon’s here and AT&T’s here.

Price: point goes to AT&T

While both carriers are selling the new iPads for about $130 more than Wi-Fi-only equivalents, they have different monthly data plan rates, and those costs can add up over the length of a year. AT&T’s mid-tier plan gives you 3 GB for $30, compared with Verizon’s 2 GB for the same price. For most smartphone users, that extra gig is extraneous, but in the world of tablet computing, it can go a long way.

For the heavy volume user, Verizon has a 10 GB plan for $80, while buying the equivalent amount of data from AT&T would cost $100. For the more conservative user, AT&T’s plans scale down to $15 per month, but that hardly seems worth it, given that you only get a measly 250 MB. If you go over your monthly allotment, both operators charge $10 per gigabyte.

Update: If you want to take advantage of the hotspot capabilities in the iPad, Verizon is your only choice for now. It allows you to tether other Wi-Fi devices to the iPad’s 4G connection at no extra charge. That doesn’t mean AT&T won’t offer hotspot capabilities in the future. It’s just a question of whether AT&T will require customers to sign up for an additional tethered data bucket as it does with smartphones.

As for complete mobile broadband freedom, neither one of these operators is going to let you make the wheels rip on your new iPad, unless you’re willing to pay dearly for it. While LTE connectivity is going to be a nice perk for those who buy it, its faster speeds mean consumers will be eating through their plans at rapid clips. So count on spending a lot of time on Wi-Fi with your new 4G iPad.