SmartAboutThings writes: Microsoft launched the Surface Pro 2 tablet in October 2013 with several hardware upgrades, like the new 1.6GHz Core i5-4200U processor specifically optimized for longer battery life and increased performance. Three months later, Microsoft decided to upgrade the CPU with a 1.9GHz Core i5-4300U unit that would be capable of taking these improvements even further. Albeit Redmond has kept a low profile for the somewhat significant improvement, tech savvy buyers were aware of the change. Now, according to some new reports, it seems that the company is still shipping the old models to buyers, despite the fact that Microsoft has promised to deliver only upgraded models featuring the new CPU. The new processor is said to come with 20% higher clock speed and 15% to 20% better overclocked clock speed.