Forget a year, oh what a difference six months makes. Last summer, Apple was riding the euphoric waves of another successful iPad launch, selling as many 3rd-generation, "new" iPads as it could make. The post-PC world was its oyster. Android tablets had come and mostly gone, starting with the ill-fated Motorola Xoom, with Samsung and Asus rekindling Android lovers' hopes with the Galaxy Tab and Transformer Prime respectively. While the collective reviews weren't all bad, the market's judgment was harsh: through last year, iPads outsold Android tablets by three or four to one.

But Google isn't HP; it didn't cut and run. Instead it methodically improved Android's tablet features -- recall that early Android devices ran a warmed over version of the smartphone OS -- while simultaneously taking on a bigger role in hardware design and development. The first fruits of this new, best of Google strategy, was the Nexus 7; a compelling mini-tablet that beat Apple's entry to the 7-inch space by four months and whose sales figures, estimated to be more than 5 million by the end of the year, exceeded all expectations. Next up, a full-frontal assault on iPad dominance in the 10-inch market via the Nexus 10.

I've been living with a Nexus 10 for the past month, but after almost two years of iPad use, the last nine months with the third-generation, Retina Display edition, my tablet expectations are high. The Nexus didn't disappoint. On paper, the Nexus bests both the third- and tweaked fourth-gen iPads on almost every front: higher resolution screen, faster processor, more RAM, better cameras, it's even thinner and lighter for crying out loud. It smokes even the souped up fourth-gen iPad by almost 40% on Geekbench 2, but we all know that there's far more to the tablet experience than specs and benchmarks. On those measures a cheap knockoff watch is as good as a Rolex. No, what really completes the Nexus package is Jelly Bean, an Android version that finally rivals iOS for speed, polish, responsiveness and features.

[ This question is easier than you might think to answer: Should You Buy A 7-Inch Or 10-Inch Tablet? ]

Jelly Bean bears the fruits of Google's Project Butter, rectifying the frustrating stutters, pauses and battery drain that plagued Android 2.x. But this Android redux isn't just iPad smooth; its new features palpably improve the tablet experience.

As I wrote in a recent InformationWeek smartphone report, "while 4.1 includes a raft of small changes, the big new feature is Google Now, essentially a combination of predictive search (Google Instant) and Siri-like voice activation (Voice Search)."

Google Now, which is just a home-screen search widget away, attempts to provide information you're likely to be interested in, things like weather forecasts, traffic reports, sports scores, current event listings, before you actually do a search. While the concept seems a bit gimmicky, the implementation shows promise; it's not bad for a first release and will undoubtedly get better at prediction (as you use it) and functionality (as Google bangs on the code) over time. In contrast, Voice Search does to Siri what Google Maps did to Apple's subpar iOS 6 effort: I found it much faster, somewhat more accurate and far more aesthetically pleasing, as Google ditches Siri's robotic voice for something akin to AT&T's Jane the Time Lady).

The notifications bar is another area where Android excels. On iOS it's an afterthought that I seldom use, but it's been integral to Android from day one. In 4.2, the incremental Jelly Bean version developed for Nexus, the bar's been bisected. On the right, a quick swipe provides access to system-level information like battery level, network information, airport mode and the system settings panel. On the left is an application-specific bar showing everything from new email snippets and calendar events to Facebook and news feed updates.

But all isn't perfect in the land of Jelly Bean. Although Android is now every bit as responsive as iOS, it's still not as reliable. Lockups are at least a once-a-week occurrence, something that never happens on the iPad, where the only time I ever reboot is for an OS update. Like most OS problems, the freezes are unpredictable, but most often occur in the browser; maybe Android Chrome isn't quite as stable as its PC counterpart.

Apps are another frustration. It's not that Android per se has an app gap; there are plenty of great titles. As I wrote in a recent column about the Samsung Galaxy Note II, most of the major iOS titles are also available on Google Play -- and for those MIA, there's almost certainly an excellent substitute.

No, the problem is that most are still built for small-screen phones, unable to take advantage of the Nexus 10's luxuriant 2560 x 1600 (take that iPad) screen with more pixels than most laptops. Even for those that do work on the big screen, the text is too small and often not scalable. Sometimes the developer, perhaps wisely, refuses to even support tablets at all. A couple of my iPad favorites, like Flipboard and Zite, which have Android ports that work fine on phones, will not install on the Nexus, presumably since they haven't figured out how to use the added screen real estate. Still, the app situation is hardly a deal breaker. While my Nexus 10 hasn't expanded to the five screens worth of icons that litter my iPad, I haven't found a major software or content category with significant holes.

Nor do the app scales always tip in the iPad's favor. For those of us that base a considerable portion of our online existence on Google services, Android is a stellar choice: the OS integration is tight and the native apps like Gmail, Calendar, Search and Play are arguably better than their iOS cousins. Indeed, Google brings a fresh approach to many categories like the Play Music app, which just looks cleaner and more modern than iTunes. Likewise, the large content library widget that occupies the default home screen is an incredibly convenient portal to recently accessed books, music and videos; think of it as a self-organizing pile of CDs, books and magazines on your desk. Apple, take note.

With the Nexus line, both small and large screen, Google clearly charts a compelling alternative path to Apple's tablet dominance. A market that once seemed a monopoly is now a competitive joust between quite different platforms, each with its strengths and weaknesses. While iPads still hold the upper hand, the Nexus duo provide worthy, and more affordable, alternatives. Life just got more complicated for tablet buyers.