alright well, i don;t know what the onyx2 is so im gonna compare it to the bold 9780 as in my opinion is the best blackberry ever made.
Pros for the TORCH are;
-Big screen (makes a big difference while using os 6),
-Touch screen (again, navigating os6 is much faster on a touch screen device),
-The phone is faster than the 9780
-And the combo of virtual and physical keyboard is a nice little transitional touch.
Cons;
-too heavy,
-battery life is not as good as 9780,
-phone is kinda clumsy to operate due to its weight, size and design.
-much crappier external speaker then the 9780
-left convenience button missing (big negative)
bold IV aka the 9780 Pros;
-Battery life is simply fabulous,
-weight and size of phone are perfect for a smartphone.
-full keyboard and imo the best Bold keyboard ever made.
-left convenience key
Cons;
-Smaaaaall screen. (after using the torch for a month, i could not go back)
-Noticeably Slower then the Torch.
-OS6 on a small and non touch screen is pretty crappy.
So...theres a real quick synopsis of the two phones. Personally ive been going between the two for the last month unable to decide which device to stay with however, the torch won not because its a better phone, it's not, but because os6 on such a small screen truly sucks and touchscreen is where the future of the blackberry is going. So i figure i might as well come into the present.
it depends on what u need the phone for. thats what makes the bb amazing. to each is own and theres a device for everyone.
good luck