The Z30 certainly is BlackBerry's biggest phone yet, with a 5in 1280 x 720 Super AMOLED touchscreen, and the latest 10.2 version of BlackBerry 10 OS.
The Z30 is in everyway, the Z10's larger sibling, and not just in size. It's gotten a bigger bump in the power department with a 1.7GHz quad core, Qualcomm Snapdragon S4 processor with Adreno 320 GPU comapred to the former's 1.5 GHz dual core and Adreno 250.
The Bigger the Better
That new BB 10.2 adds the new Priority Hub which learns which are the most important messages to you from email, social networks and elsewhere, then presents only the best. It has also addded a message preview function, allowing you to preview any messages that arrives while you're using another app. BlackBerry Natural Sound is also onboard and it's a feature designed to improve the sound quality of video and voice calls over BBM.