These days I’m feeling a little guilty. A little over a month ago I praised the iPhone 3G for its zippy data speeds in our full review. Since then complaints have been pilling up from iPhone 3G owners about spotty reception, seemingly random switching from 3G to EDGE data, and frustratingly sluggish Web surfing. What the hell is going on? Did we review a different device?

No. But the iPhone 3G I hold in my hand right now certainly feels like a different smart phone than the one I initially praised. And, yes, I’ve updated to the latest firmware, 2.0.2, which supposedly fixes bugs that haven’t been detailed by Apple.  I’m not quite ready to take back our Editors’ Choice award, at least until we’ve had a chance to test the next firmware update Apple promises in September, but I would certainly recommend holding off on buying an iPhone 3G until these issues are fully resolved. How dramatic is the difference between my experience with the iPhone 3G on July 9th and today? Night and day.

Take yesterday, for example. I usually start off my morning commute (about an hour and 20-minute bus ride into Manhattan from the Jersey burbs) reading the news on the NY Times app. Before my only complaint about this app was unexplained random crashes. Now my biggest complaint is that it sometimes takes forever just for the front page to load.

To make sure that the app wasn’t solely to blame, I fired up Safari and tried surfing over to the New York Times homepage, ESPN, and our own site during an evening and morning commute to and from Manhattan from Freehold, NJ. Regardless of whether the data icon at the top of the iPhone 3G’s screen displayed “E” for EDGE or “3G”, the browser took its sweet time loading these pages. In some cases, these pages loaded in about a minute (tolerable but not nearly as good as what you see on TV) and in other cases I gave up after a minute and a half (really not good).

Last but not least, I tried streaming some music in Pandora for the remainder of my trip, and just as I feared, the audio cut out several times (compared to about two or three times just a few weeks ago) and twice lost its connection entirely. I finally put the iPhone 3G away and used the Sprint data connection card on my notebook instead to surf and stream tunes.

Critics and pundits have cited several reasons for the iPhone 3G’s wonky connectivity, ranging from a bum communications chip made by Infineon, to AT&T’s patchy 3G network, to the sheer number of iPhone 3G’s online at any given time in densely populated areas. Despite the fact that I’ve found both Sprint and Verizon Wireless’ 3G data networks to be more reliable in the Northeast, I’ve tested many other AT&T 3G-enabled smart phones without encountering these types of problems, including the Samsung BlackJack II and AT&T Tilt. And although there’s no question that iPhone 3Gs likely use more data than any other type of smart phone, this doesn’t explain the sheer erratic nature of the iPhone 3G’s behavior. It certainly won’t hurt when AT&T frees up more of the further-reaching 850 MHz band for 3G data, as has been promised.

As for the reports that the latest firmware has made things worse, I’m inclined to agree, at least when it comes to the GPS connection. Last night I tried three separate times in the iPhone 3G’s Maps application to pinpoint my location and gave up after 45 seconds. About 15 minutes later, my attempt was successful within just a few seconds. It’s this kind of inconsistency that has we wondering what it will take to fix the iPhone 3G. At this point I’m not sure yet another firmware update will cut it. We need a full-scale intervention from Apple. Fast.

Are you frustrated or happy with your iPhone 3G’s data performance? Sound off in the comments.