Apple’s embargo on publications seeded with pre-release units of the Verizon iPhone ended yesterday and we are seeing early reviews from these publications.

Most of the reviews are as expected, reviewers have observed that the voice quality of the iPhone on Verizon’s network is a lot better than AT&T though download and upload speeds are slower.

Here are some of the excerpts from reviews from some of our favorite tech journalists/bloggers:

Walt Mossberg of Wall Street Journal:

• On the big question, I can say that, at least in the areas where I was using it, the Verizon model did much, much better with voice calls.
• In these many tests, despite a few Verizon victories here and there, AT&T’s network averaged 46% faster at download speeds and 24% faster at upload speeds.
• Also, because Verizon’s iPhone—like most other Verizon phones—doesn’t work on the world-wide GSM mobile-phone standard, you can’t use it in most countries outside the U.S.
• the Verizon model can’t fetch Internet data at the same time it is making a voice call, something the AT&T model can do.
• Bottom line: In my tests, the new Verizon version of the iPhone did much better at voice calling than the AT&T version, and offers some attractive benefits, like unlimited data and a wireless hot-spot capability. But if you really care about data speed, or travel overseas, and AT&T service is tolerable in your area, you may want to stick with AT&T.

David Pogue of New York Times:

• In San Francisco, the AT&T phone dropped the call four times in 30 minutes of driving; the Verizon phone never did. The Verizon iPhone also held its line in several Manhattan intersections where the AT&T call died. At a Kennedy airport gate, the AT&T phone couldn’t even find a signal; the Verizon dialed with a smug yawn. The Verizon iPhone did drop one call — in baggage claim at the Los Angeles airport. And, of course, there are regions where AT&T coverage is better than Verizon’s. But in general, my testing matches the conclusions of Consumer Reports and RootMetrics.com: the Verizon iPhone has more bars in more places.
• Apple moved the volume and Ringer Off switches a fraction of an inch to accommodate the C.D.M.A. antenna inside. It’s not a big deal, but those buttons no longer fit existing AT&T iPhone cases. (Contrary to blogger belief, the redesign doesn’t help with the famous Death Grip issue, in which holding the phone in a certain way makes your signal bars drop. Then again, the problem emerges only when you’re in a very weak signal area, so you’ll see it less often on Verizon. I couldn’t reproduce it at all.)
• When you exchange long text messages with non-Verizon phones, they get split up into 160-character chunks. G.S.M. phones are smart enough to reconstitute those chunks into one more readable, consolidated message.
• You can’t talk on an C.D.M.A. phone while you’re online. That is, if you’re on a call, you can’t simultaneously check a Web site or send e-mail over the cellular network — and, annoyingly, the Personal Hotspot feature cuts off. (It reconnects when you hang up.)
• For business travelers, the fourth C.D.M.A. difference is the most disappointing: not many other countries use C.D.M.A. The Verizon iPhone works in about 40 countries, including Mexico, Canada and China; AT&T phones, on the other hand, work in 220 countries.

MG Siegler of TechCrunch:

• This Verizon version of the iPhone 4 seems to have none of the same antenna issues. Try as I might, using the “death grip” and every other grip I can actually do, I can no longer reproduce the same attenuation problem that the previous iPhone 4 model had.
• The single most important thing that would-be AT&T switchers and some new iPhone customers will want to know is: how does it compare to the AT&T version in terms of signal, dropped calls, data, etc. The answer, at least in my neck of the woods (again, San Francisco), is very, very good.
• It’s true, you definitely cannot make a call and surf the web at the same time on the Verizon iPhone. To some people, this will matter. But I have really never seen this as a huge issue.
• There’s no question that AT&T’s network is faster than Verizon’s for data transfers — both up and down. I’ve tried this all over the city a number of times. AT&T is faster. But — and this is a very big but — in order for AT&T to be faster, it needs to have a signal. And again, that’s simply not the case in large parts of the city. So speed or not, Verizon still wins this battle hands down in my book. I’ll take Verizon’s coverage over AT&T’s speed any day.
• The one other issue brought up when taking about CDMA versus GSM is that the CDMA version of the iPhone won’t be able to roam internationally. For many countries, particularly those in Europe, that is true.

We would love to find out if these early reviews have convinced you to switch to Verizon or stick to AT&T, so please drop us a line in the comments section below.