HTC released its Sensation XL with Beats Audio in the UK market on Oct. 6. Despite not hitting the U.S. shores officially, the HTC Sensation XL with its huge 4.7-inch screen is expected to give tough competition to Apple Inc.'s iPhone 4S worldwide.

The HTC smartphone is not expected to be offered from any of the carriers of United States, but consumers can get unlocked version of the phone and make it compatible with the AT&T network.

Sensation XL is the second HTC smartphone to be released with the Beats Audio technology. HTC had invested $300 million in Dr.Dre's Beat Electronics, which produces quality headphones for music devices.

HTC Sensation XL, which runs on Google Inc.'s Android 2.3.5 Gingerbread OS, is adorned with 1.5 GHz Scorpion processor, Adreno 205 GPU, Qualcomm MSM8255 chipset, 4.7-inch S-LCD capacitive display, 768 MB of RAM, 16 GB of internal memory, 8-megapixel rear-facing dual-LED flash camera with 720p video capture and 1.3-megapixel front-facing camera for video calls.

On the other hand, Apple received overwhelming positive responses for iPhone 4S, which was unveiled on Oct. 4 instead of the eagerly-anticipated iPhone 5, that sold 4 million units during the opening weekend. The smartphone missed some prominent specs like edge-to-edge design, a larger display, 4G LTE and Near Field Communication (NFC) technology.

However, iPhone 4S featured some important upgrades that were rumored to be a part of the imaginary iPhone 5, like the 1GHz dual-core ARM Cortex-A9 processor, PowerVR SGX543MP2 GPU, an Apple A5 chipset and an 8-megapixel camera. It also has a 3.5-inch TFT Retina multi-touch display and is loaded with the latest Apple operating system iOS 5.

The Apple smartphone also comes with alternating antennae for better call reception, CDMA and GSM support, a personal assistant called Siri, iCloud and Bluetooth 4.0 wireless technology. The phone has a Li-Po 1,420 mAh battery, with 8 hours of talk time on 3G networks and up to 14 hours on 2G networks (GSM).

Let's look at the specifications of Apple iPhone 4S and HTC Sensation XL.

Display: Sensation XL touts a 4.7-inch S-LCD Gorilla glass touch screen with qHD 800 x 480 pixels resolution at about 199 ppi pixel density. iPhone 4S, when compared, has the same 3.5-inch TFT Retina multi-touch display that may give a resolution of 960 x 640 pixels at 326 ppi density.

Size: Sensation XL comes with 132.5 x 70.7 x 9.9 mm dimension and weighs 162.5 grams, while iPhone 4S comes with 115.2 x 58.6 x 9.3 mm and weighs 140 grams.

Processor: iPhone 4S, which comes in an A5 chipset, is powered by 1GHz dual-core ARM Cortex-A9 CPU, PowerVR SGX543MP2 GPU. On the other hand, Sensation XL features 1.5 GHz Scorpion processor, Adreno 205 GPU, Qualcomm MSM8255 chipset with 768MB RAM.

Operating System: Apple's iPhone 4S runs on the newest iOS 5 that comes with 200 new features that will include an improved Notifications System, Newsstand and iMessage. On the other hand, Sensation XL runs on the Android 2.3.5 Gingerbread.

It is been officially known that Sensation XL could be upgraded to the latest version of Google Inc.'s smartphone operating system, Android 4.0 Ice Cream Sandwich, in the early 2012. Ice Cream Sandwich is a combination of Gingerbread and Honeycomb in one unit. Android Head of Engineering Mike Claren announced that the new OS is Google's most ambitious release to date.

The newest features arriving with Android 4.0 include widgets in a new tab, a customizable launcher, Gmail with offline search with a two-line preview and new action bar at the bottom, better voice integration, improved copy and paste and a new tabbed Web browser that allows up to 16 tabs.

Camera: Both the smartphones sport a rear-facing 8-megapixel camera. HTC Sensation XL has dual-LED flash with 720p video capture capability, while Apple iPhone 4S has LED flash with 1080p HD video capture capability. For video calls, Sensation XL sports a 1.3-megapixel front-facing camera while iPhone 4S comes with a secondary VGA camera.

3G: Apple iPhone 4S has HSDPA 14.4 Mbps, HSUPA 5.8 Mbps support and also has CDMA EV-DO Rev. A (800, 1900 MHz) technology, while Sensation XL has HSDPA 14.4 Mbps, and HSUPA 5.76 Mbps.

Storage: iPhone 4S has fixed 16/32/64 GB internal storage, while Sensation XL has a fixed 16 GB internal storage.

WLAN/Bluetooth/USB: iPhone 4S has Wi-Fi 802.11 b/g/n and Wi-Fi hotspot, while Sensation XL has Wi-Fi 802.11 b/g/n, DLNA, and Wi-Fi hotspot. Sensation XL has Bluetooth 3.0 version with A2DP along with microUSB 2.0 version, while iPhone 4S has advanced Bluetooth version 4.0 with A2DP along with USB version 2.0.

Battery: The Apple smartphone has a Li-Po 1420 mAh battery, with 8 hours of talk time on 3G networks, up to 14 hours on 2G networks (GSM) and a standby time of 200 hours. On the other hand, Sensation XL comes with a standard Li-ion 1600 mAh battery with 6.5 hours on 3G networks, up to 11.5 hours on 2G networks (GSM) and a standby time of up to 360 hours.

Additional Features: Sensation XL comes with Gorilla Glass display, HTC Sense 3.5 user interface, multi-touch input method, proximity sensor for auto turn-off, accelerometer sensor for UI auto-rotate, touch-sensitive controls, gyroscope sensor, SMS (threaded view), MMS, Email, Push Mail, WAP 2.0, HTML, xHTML, A-GPS support, Beats Audio, Beats headset, Digital compass, active noise cancellation with dedicated mic, MP4/H.263/H.264/WMV player, MP3/eAAC+/WMA/WAV player, Google Search, Maps, Gmail, YouTube, Calendar, Google Talk, Facebook and Twitter integration, and Adobe Flash support.

On the other hand, Apple iPhone 4S comes with scratch-resistant oleophobic surface, multi-touch input method, accelerometer sensor for auto-rotate, Three-axis gyro sensor, proximity sensor for auto turn-off, iMessage, SMS (threaded view), MMS, Email, Push Email, HTML (Safari), A-GPS support, GLONASS, micro-SIM card support only, scratch-resistant glass back panel, active noise cancellation with dedicated mic, Siri natural language commands and dictation, iCloud cloud service, Twitter integration, Digital compass and Google Maps.