So Verizon has an iPhone: Empires (of technology) have risen and fallen since Apple introduced its iPhone in 2007, and the question constantly on everyone's lips: When will Verizon get a model that works on its network? The answer: 3 February for existing customers and 10 February for new ones.

The CDMA-based iPhone has piles of tradeoffs, but these aren't necessarily worse than using a GSM iPhone on AT&T or other networks around the world.

The Downside

The ViPhone doesn't have LTE. No phone has LTE. We're not going to see LTE-based phones with decent battery life and size for several months, and the early ones will be monsters of compromise. There is no agreed-upon voice standard for LTE networks yet, which means Verizon will make compromises in whatever voice option it picks (initially) before later upgrading to something more universally supported. I don't expect an LTE iPhone until 2012, because coverage and other tradeoffs won't make it desirable until then.

You can't talk and use 3G data at the same time. Verizon opted for EVDO (Evolution Data Only), which tells a story with its name. Voice is handled separately and can't be used simultaneously. Wi-Fi and voice can be used at the same time.

It's Verizon Wireless, for cripe's sake. Verizon has a history of offering less-than-forthcoming information about its service plans, and is in the middle of settling a dispute in which it denied for years charging people $1.99 and other fees for inadvertent usage of mobile data without a plan (when pressing a conveniently located button that's on every featurephone). People don't like any carrier, but Verizon didn't make itself any friends with this.

We don't know pricing plans yet. Verizon's 3G service plans aren't bad, but they aren't enormously better than AT&T's unless you use a ton of data each month.

Worldwide roaming isn't an option. Despite being 45-percent owned by GSM carrier Vodafone, the ViPhone won't work on most networks worldwide because it's CDMA only. It's odd that with Vodafone selling many millions of iPhones into other markets, Verizon Wireless, Vodafone, and Apple wouldn't have teamed up to offer both. There are chips, from Qualcomm notably, that allow GSM/CDMA switchover. You won't be able to use your ViPhone in Canada or Mexico, notably, and you can't swap out a SIM in GSM markets for another carrier, something that carriers allow or make easy in some markets, or that you can jailbreak to allow. (Update: Canada and Mexico do have CDMA operators, and Verizon supports roaming. Coverage in Mexico is quite limited for voice and data; in Canada, there's broader availability, but 3G data isn't everywhere.)

AT&T has a path to faster service, with HSPA+ (21 Mbps) overlaying HSPA 7.2 (7.2 Mpbs) as the year goes on. Verizon is stuck at 3.1 Mbps EVDO Rev. A until it has a sufficient LTE footprint to jump its customers to that. (AT&T and Verizon will both require new hardware for faster networks, though. An iPhone 4 will not, to my knowledge, be firmware upgradable to HSPA+.)

The Upside

If you live in an area with poor AT&T coverage and great Verizon coverage, which likely amounts to tens of millions of people's homes and workplaces around the US, then you are suddenly able to own an iPhone of your very own. AT&T's coverage can be sketchy in many parts of the country, notably exurbs and large parts of New England.

Verizon and Apple are offering a mobile hotspot feature (pricing not yet known), which lets the iPhone be used as a Wi-Fi hotspot, just like a MiFi, or Android 2.2 phone, or several other smartphones. This lets up to five devices connect. GSM networks and the GSM iPhone could support this feature, too. Apple has been keeping this in its back pocket, perhaps to save for Verizon. (I don't believe AT&T, unique among the carriers, has any phone with a mobile hotspot feature enabled, nor does it offer a MiFi or similar router to the general public. Correction: AT&T reminded me via email that they had added a MiFi to their product line last November.)

Heavy data users will have an unlimited plan restored to them if Verizon offers its $30/mo unlimited data plan to new iPhone users. AT&T removed that plan for new subscribers in June, and has a 2 GB/mo plan for $25, with $10/GB overage fees (charged by the whole GB for any fraction).

The Upshot

Verizon will sell many millions of its CDMA iPhone to existing customers (upgrading from featurephones and sidegrading from other smartphones) and new customers (who have never owned a smartphone or are fleeing AT&T, cancellation fees be damned).

Verizon has the best and most solid 3G network in the US, proven time and again by independent third parties. AT&T has continually improved its network coverage and speed, and has great plans for 2011.

Can we have some competition now, please?