VisionBase loses me with this claim on the product's data sheet, "DVR’s exporting via USB instead of CD/DVD present the risk of transferring viruses or malware. DVR hardware in most instances are capable of recording and displaying a much clearer and sharper image when viewed via video, VGA and HDMI, PREVIS takes advantage of this fact allowing recording of the audio and video in original high-resolution at up to full HD 1920x1080 pixels." It's like a firearms examiner saying that a picture of a gun is better than the actual gun for forensic examination cause their hands might get dirty. Seriously? I'd rather have the data, the actual evidence, than a picture of that evidence - as I've said many times on this blog.
Then there's this:
From the looks of it, Previs allows for the user to load all of VisionBase's software and perform clarifications and case management in the field. The laptop version of Previs breaks the capture device out as a separate piece of hardware, like the Field Kit. Both companies have bags of cables and connectors that ship with the units. VisionBase adds a handy trolly - your tip that the full version of Previs might be quite heavy.
No hint at pricing. But, as they're a UK based company, they probably can't compete too closely with the field kit on price. Also a factor for US agencies is the ability to buy and get service from a US vendor. When last I dealt with VisionBase US, there were just a few employees in Florida ... and no technicians outside of the UK. Perhaps that's changed. Nevertheless, its something to consider.