Tablet Vs PC, Which to Pick ?
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Notebooks, laptops and desktop PCs are still the best productivity and content creation devices. The main reason is that office and productivity softwares are full featured in notebooks. Organizing your files such as documents, photos, videos and MP3 is a breeze. Using a mouse is also an advantage in engineering software such as AutoCAD. Typing in a physical keyboard is a big plus. Disadvantages of PCs are they are heavy and have short battery life. Most mobile PCs have 2 to 5 hours battery life, except for some notebooks and all ultrabooks which are capable of 8 to 10 hours battery life.
Tablets are best used for media consumption especially on the go although netbooks and ultrabook are portable also. Maybe the best instance is when you are sitting in the couch or lying on your bed. Advantage of tablets are most have good battery life of 4 to 10 hours. Disadvantages of tablets are they are not full featured in terms of productivity and office software and unavailability of full featured expansion such as ports.
Android Tablets
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I have use Android Cupcake (version 1.5), Donut (1.6), Froyo (2.2) and Gingerbread (2.3) in my phone and it seems there is a lag in the user interface. I hope that the latest version 4 of Android (Ice Cream Sandwich) fixes this one. Android also need a much higher hardware requirement compared to others. Dual core processors are standard now and even quad core processors are available. Support for productivity application is also limited.
Several manufacturer's have different models and sizes. If you want a 7" and a 3G sim card slot, Samsung Galaxy 7.0 Plus is a good tablet. If you want a 10", Acer Iconia Tab A100 is preferable. Now, if you want the mightiest, then Asus Transformer Prime is the best choice.
iPad
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You can not still make it as an external hard drive and Microsoft Office and Windows application support is second to none. I only notice that iPad is not available in smaller tablet form factor (such as 7 inches) and the iOS is almost the same when it is released 5 years ago. UI is base on icons and buttons. Cost, memory card slot unavailability are also cons.
Discounted prices is now available to iPad 2. If you have own an iPad 2, there is no reason to upgrade to iPad 3. But if you own an iPad 2, faster processor and graphics, front camera for self-portrait shot and better rear camera are the reasons to upgrade.
BlackBerry PlayBook
Sometimes, when I open multiple tabs in the browser, it crashes. Maybe it happens only on my device or a software fix is needed. Availability of native application is also a disadvantage. The PlayBook is only available in 7 inches. 3G/4G sim and memory card slots are not supported although tethering and bridging are supported.
This is the best time to buy a PlayBook, OS 2 is just released and the prices of 64 gb now is comparable to prices of 16 gb early this year.
Windows 7 / 8 Tablets
If you will use your tablet for productivity and office applications, then this is the top choice. Full support for MS office, AutoCAD, Primavera, PhotoShop and usb devices such as flash drives and mouse. Memory card slot is supported.
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The main disadvantage of Windows 7 tablets are the user interface. Windows 7 buttons and UI is too small for touch usage. This may change in the upcoming Windows 8 OS which features a revamp UI specifically designed for tablets.
If you want a Windows tablet that will support windows snapping in the upcoming Windows 8, Samsung Series 7 Slate PC (i5 2nd gen processor) is the choice but it is pricey. Some devices such as Acer Iconia W500 (AMD Dual Core C-50 1 ghz) will not support windows snapping in Windows 8 because its resolution is lower than 1366 x 768.
Summary
If you have money and you will use it for media consumption such as web browsing, games and reading e-books, buy an iPad (iOS) or Asus Transformer Prime (Android)
If you want great customization on user interface and OS, buy an Android Tablet like Samsung Galaxy Tab 7.0 Plus, 7.7, 8.9 and 10.1 on a higher price and Acer A100, A200 and A500 on a cheaper price. LG, Toshiba, Motorola also have some models.
If you want a bang for a buck and an added integration if you own a BB phone, your best choice is a PlayBook.
If you really need office and productivity applications but it's ok with you the small buttons and odd interface for touch (until the release of Windows 8 later this year), a Samsung Series 7 Slate PC is a good but pricey choice.
Generic and cheaper tablets usually have resistive screen, slower processor, smaller RAM and flash storage and outdated OS.