iPhone 5 Vs iPhone 4S: Top five reasons why you should upgrade? Reuters

There are two yet-to-be-released Android smartphones - the HTC One X and the Samsung Galaxy S3 - which are expected sometime in Q2 this year and should dominate the smartphone market. Meanwhile, the release of the iPhone 4S helped Apple re-write some sales records and led to impressive Q1 sales figures.

However, with the iPhone 5 expected by the end of 2012, the One X and the S3 (with quad-core processors and similarly high-tech features) could be set to disturb the iPhone's traditional dominance. Users may just be waiting for the former two devices, when time comes to upgrade from the iPhone 4S.

HTC's and Samsung's phones, with 4.8-inch screens, more RAM, 1.5GHz quad-core chipsets, Ice Cream Sandwich (Android 4.0), card slot and LTE 4G support, could attract even hardcore Apple fans. In addition, both the above devices are thinner and weigh less than Apple's product. Moreover, the S3 can offer users the NFC feature.

The gamble HTC have taken with the One X remains its advanced camera technology, which is an 8 megapixel unit that can record 1080p video and capture photographs, in under a second.

Reports suggest HTC's One X and One S will be available with Orange, T-Mobile, Vodafone, O2 and Three, in the UK, sometime in April. However, online retailer Carphone Warehouse will have all three versions (including the One V). The phones are expected to be priced at around £500 (One X), £450 (One S) and £260 (One V). Such is the demand for HTC's new smartphones that all major UK networks have been busy stocking up on their top two models. Meanwhile Clove Technology is planning to offer the HTC One X for £410, the HTC One S for £375 and the HTC One V for £220.

In the US, the HTC One X will be available on AT&T's network in the coming months, while the HTC One V is heading to T-Mobile. However the One X going to be featured on AT&T will have only a dual-core chip. This is because the original Nvidia chip was found to be incompatible with AT&T's 4G LTE hardware.

The Galaxy S2 cut into sales of the iPhone 4 last year. The same may happen this year, with the S3. What it could come down to is pricing. It is widely expected the S3 will cost a little more than the S2 when it was first released. This means a free phone would probably be available (with contract deals of between £36 and £41 line rental costs per month). Finally, international carriers like Cell C are hoping the S3 will hit shelves in July, although the announcement itself may only be made in April or June.