As you have a MacPro I would probably advise you get a Kona 3. Unless you wanna unhook a device and use it with a Laptop in the field (in which case that's IoHD)
The IoHD is really about portability and it's unique ability to capture ProRes in hardware connected to a MacBook Pro.
Otherwise the Kona 3 opens up other formats (uncompressed HD, DVCPro HD etc.) as well as 2k, dual link, keying advantages with red workflows etc. Even if you don't want them now it's an option for the future. And yes is does have raster 'acceleration' for DVCPro HD, HDV and RTFX. The IoHD does not because it really is about ProRes for HD (so the answer is to capture these format to ProRes - see below).
You could also take a look at the Kona LHe which is less money (not that the K3 or IoHD are expensive in my book). This does not have 2k, some of the Red advantages of the Kona 3 and has only hardware down-conversion, but still has the raster stuff as above uncompressed HD and is good for analog connectivity to cheaper cameras (Kona 3 is digital only, though you can buy AJA converters to go with).
Best to check the Kona models here:
http://www.aja.com/html/products_macintosh_kona.html
But either way both XDCAM HD or HDV are 8bit long-GOP codecs and are at best a hassle or at worst complex for computers to edit with, and DVCProHD is not full raster so you might do better to capture them to ProRes which is iframe and 10 bit full raster 1920 x 1080 unless you are doing the most basic edits. Then if you have to push some colours add graphics you'll have a better chance and the computer will edit better with ProRes HD 422.
Many of these codecs are good but designed with the limits of linear camera tape. ProRes is designed for editing HD with pretty much no visual difference to uncompressed HD but at uncompressed SD bandwidth.
Best regards
Matty Causon
Phosphor
European Business Management for AJA Video Systems Inc.
