Both capture devices were used with the same capture software GamerCap www.gamercap.com to make it a fair playing field as the Roxio software is crap
I choice forza 4 as it's one of the best looking games on the XBox 360 plus it was easer to capture an identical video and with the help of VideoReDo to edit i had two identical game captures which were then put together with Adobe Prem Pro
Well i've sat and watched the video a few times now and have to say it's an easy draw and the only difference i can see is the Roxio has a slightly richer colour balance where the Hauppauge is more natural
So what one would i buy ?
Well i have both, i first bought the Roxio and used for a few months but the included software will drive you potty "it's a dogs dinner" so gave up and got myself the Hauppauge Rocket which i've been using for the last few weeks which has the added benefits of capturing to a PC or as a standalone device to capture to a flash drive plus it has a mic input with is handy to add commentary to your gaming videos so in the end i would go for the Rocket but there is a "But" and that's where GamerCap Capture Software comes into the game as when used with the Roxio it brings the Roxio back into the game due to how easy it is to use plus it lets you record gamer commentary from a mic plugged into your PC which is then added to the video capture something the included Roxio doesn't do "shame on you Roxio"
So in the end i would buy the Hauppauge Rocket but if funds only allow for the Roxio just make sure you also buy GamerCap software to use with it and you will still be happy
PS I use GamerCap all the time now even with my Hauppauge Rocket as it's such a great bit of software