n.b. I have also used Sony Movie HD Suite and Sony Vegas Pro. The System I am running is Windows7 64 bit, i7 930 (2.8 gig) CPU with 12 GB ram.
PD9 Ultra 64 is the first consumer Movie editing program that runs on 64 bit code. (You need a 64 bit operating system to run this, otherwise you have to buy the 32 bit version.) The Sony Consumer program is only 32 bit while the Professional program (Vegas) is available as 64 bit as well as 32 bit. The 64 bit program allows the program to access more system memory, allowing the program to render High definition video much more easily ( a problem I had with the Sony consumer program,) and allows you to have more video and audio tracks/ effects on the time line.
I have found that it installed (slowly) but with no problems and the program itself does not conflict with any other programs on my computer (unlike the Sony alternatives, but this has been resolved).
I have found that PD9 is more intuitive to use vs the Sony alternative as each stage of the movie edit is segregated into the four categories of Capture, Edit, Produce and Create Disc.
The Software does come with a paper manual which does give you the basics on how to use the software and there are quite a few YouTube movies online. There is also a Cyberlink forum for PD9.
One feature of PD9 is the GPU (graphics card) render feature which can cut down render times. (I found Sony Professional 64 was faster at rendering than Sony Movie HD (32 bit) by around 15 %.)
On initial testing, comparing PD9 64 bit to Vegas Pro 64 bit, I found PD9 rendered files significantly faster than Sony Vegas (using CPU render only on WMV files e.g. rendering a 15 minute 720p video to 640 x480, PD9 took 3 minutes 40 seconds while Sony Vegas Pro took 5 minutes 15 seconds). Enabling the GPU to help with the rendering can further reduce the render times by up to 40%! But I have found on some large files (4gigabyte files/ 3hrs of video), using the GPU to render can also actually increase the render time. Weird! So check GPU and CPU render estimation times before choosing which render method you are going to use.
Nvidia and ATI/AMD cards are supported (please check for your card though,) but there is a caveat, the GPU render only works with H264 AVC (AVCHD- m2ts files) and MPEG4. There is no GPU render with AVI, WMV, MPEG 1 or 2, .MOV! (Although Sony Vegas Prof supports GPU render I have personally found the render times to be un-inspiring.) The only other program that I know that supports GPU render is Adobe Premiere, a professional editing program that also costs around 12 x price of PD9.
I have found that PD9 also supports a wider range of AVI codec files than the Sony programs e.g. Xvid and Dvix. (You cannot open these files in the Sony Programs.)
With PD9 you can only choose the standard size render templates e.g. 800x600, 720 x 576 to High definition levels e.g. 1080p etc and you cannot choose an unconventional custom size e.g. 800x450, 640 x360. You can change the bit rates eg constant, variable, and how high or low the bit rate is for the video and audio. ( The Sony programs allow you to alter the template size and bit rate.) I have also found adding text to the video is more `crude' in PD9 vs Sony.
While using the Sony Program I haven't found any bugs yet. With PD9 I have found that enabling the preview widow for the final render, if you minimize PD9 and then maximize the PD9 window, the render will stop then restart itself from the beginning! So if you want to browse the internet, do not enable the preview window when you render.
Overall I found PD9 to be easy to use, faster at rendering most types of video and stable, but you do lose some flexibility/ sophistication vs the Sony programs.
PD9 also comes with a simple sound editing program.
Conclusion: Overall I think this is a well designed and user friendly editing program and is worth considering if you want an easier/ quicker life, but you do lose some flexibility/ sophistication over the Sony alternatives.