RIM's attempts to get a cellular-equipped version of the BlackBerry PlayBook have been troubled, to say the least. The company signalled its intentions around Mobile World Congress last February, only to watch as carriers backed off -- partly as RIM focused its attention on LTE, and partly after carriers grew skittish over sales of the WiFi version. A year and a half later, we finally have an LTE version, and with a faster 1.5GHz processor to boot. But do 4G data and a processor bump make all the difference? And does the upgrade stand a realistic shot in a competitive field that has moved on since the original PlayBook? We'll find out in our hands-on.