So, what are the software updates, then? Well the first I want to mention is camera related.
This being a Cybershot phone the camera is pretty good. The sliding lens cover is a real plus point both because of its smooth action and the protection it offers to the lens and Xenon flash.
Launch the camera software, and just as with the original C905 you've got some shortcuts on the navigation key for flash/redeye, auto/macro/face detection/infinite focus, exposure settings and the timer.
There are two further buttons above the screen. One cycles you through shooting modes (normal, smile shutter, smart contrast, BestPic, panorama and frames) and the other cycles through scenes modes (auto, twilight landscape, twilight portrait, landscape, portrait, beach/snow, sports and document).
The quality of images from the 8-megapixel camera seems a little improved. I've rephotographed the coloured dish, chair and plant from my review of the C905. The macro mode deserves a special mention at being much better at capturing detail this time around.
The newcomer to the camera portfolio is Smile Shutter which, you've guessed it by now, takes a photo when your subject is smiling. OK, it's not enough to set the heart racing, and you do need to be quite close to the subject for it to work, but it does bring the C905 up to standard with other top-end cameraphones.
Another newcomer is Snapfish which you can use to order prints of the photos you've taken. The software client is easy enough to work with, but I tend to prefer to take a look at photos on a PC first just to check the quality on a screen larger and more capable than the albeit very passable 240 x 320 pixel 2.4in one here.
The C905 Plus remains a 3G handset with HSDPA. There's no front camera for two-way video-calling so when you do make a video call, the person you are speaking to sees what the main camera shows from the back of the phone. You can either turn the camera to face you, or see the caller by looking at the screen, but not both.
Wi-Fi is here as well as GPS. There is an updated trial version of the Wayfinder navigation software, pre-installed Google Maps, a tracker you can use to help with sports training, and an application called Near Me, which finds nearby services.