The Apple iPad has only been physically available to the general public for a few weeks, and the HP Slate is still a prototype waiting for a launch date, but that hasn't stopped the two from being compared head-to-head as the defining epic battle for tablet supremacy. An early review of the HP Slate suggests that the iPad has the crown locked up, though.
Apple did not invent the tablet. The Apple iPad is not alone. There are a wide variety of tablet devices already available or coming soon. However, ever since Steve Ballmer unveiled the HP Slate at CES earlier this year--when everyone was expecting to see the rumored Microsoft Courier tablet--it has become the poster child for all things anti-iPad.
Truthfully, it's a false comparison. The two are both tablet devices, and they both deliver many of the same functions, but it's an apples and oranges comparison of different devices, with different goals, and different intended audiences. You don't see any epic comparisons of the HP Slate and the Barnes and Noble Nook even though they're both tablet devices.
It is a little like an argument between a building contractor and a race car driver over whether a Ford F150 is a "better" vehicle than an Audi R8. The contractor can argue that the F150 has superior cargo space, a larger passenger cabin, and significantly higher towing capacity, while the driver can point out the sleek aerodynamics and exceptionally higher top speed of the R8. Both would be right because "better" depends on the intended use and is in the proverbial "eye of the beholder".
HP has unveiled videos illustrating that the Slate is everything the iPad isn't--USB ports, expandable memory with SD card slots, support for Adobe Flash, able to run all of the software normally run on a Windows desktop PC. It's a "real" computer.
A leaked HP document comparing the features and specifications of the Slate and iPad head-to-head, though, shows the weaknesses of the Slate, and an early review of the Slate from a Mexican site with a Canadian domain suffix (a review which was subsequently taken down at HP's request) was notably unimpressed--deeming it essentially a netbook without a keyboard. Bottom line, it's a "real" computer.
So, which is a better device for mobile business professionals? Well, business professionals that need a fully functioning Windows operating system, or want a camera--or two, or the ability to use USB devices and SD memory cards, or feel that Adobe Flash is a business-critical application can choose the HP Slate--the Ford F150 of tablets.
Business professionals that want a thinner tablet with a larger display, with instant-on access to the device, faster speeds, longer battery life, and access to more than 150,000 apps--most of which are cheap, or even free--can choose the iPad--the Audi R8 of tablets.
There is nothing wrong, per se, with either choice. The contractor is right that the Ford F150 is better--for him--and the race car driver is also right that the Audi R8 is better--for him.