The Envy x2 has never been our favorite Windows 8 tablet, but that hasn't stopped HP from selling loads of them. The device has been such a success, in fact, that the company is expanding the x2 series to make room for two follow-on products: the Split x2 (a Windows 8 hybrid) and the SlateBook x2 (an Android tablet). Starting with the Split (pictured above), this is the first time HP's made a laptop / tablet hybrid with a laptop processor inside, though
