The Blackmagic Design Intensity isn't strictly a game capture device. It's designed to capture all video and is geared toward audio/video professionals. As such, it doesn't have some of the ease-of-use features you might expect to see. It can also be difficult to set up. Once you have everything working, it's hard for other HD game capture devices to compete with it, but there are definitely some flaws here.
Perhaps the most notable flaw for a game capture device in this price range is that the Intensity can't record video at 1080p and 60 fps. It can do 1080p and 30 fps or 720p and 60 fps. This is odd because the Intensity uses a USB 3.0 port. Other game capture devices with USB 3.0 ports can handle 1080p and 60 fps. Many live-streamers and YouTubers aim for 60 fps because it provides a much smoother experience for viewers.
On the other hand, the Intensity has inputs and outputs for just about every connection you'll need. Old consoles or new, you should be able to connect them to the Intensity. From there, it's a matter of configuring your computer correctly, which can be a bit difficult. Like some other game capture devices, the Intensity requires a specific CPU chipset to work. Make sure that your computer is compatible before buying this product.
Thanks to the USB 3.0 connection, you shouldn't experience any latency when playing and recording at the same time with the Intensity. That's crucial, because the Intensity doesn't have HDMI pass-through. You'll need to play your games on the same screen that the capture software is running on. This isn't a problem for everyone, but it can be distracting at times.
While the Intensity comes with some capture software, it doesn't offer much besides the very basics. To do anything special with your recordings, you'll need to use a separate application. The included software doesn't have any streaming capabilities either, so you'll have to sort that out on your own as well.
The Intensity is compatible with most streaming and editing software. You can open up Open Broadcaster Software (OBS) and get right to streaming while playing and recording. You can also use your editing software of choice. The Intensity lets you save your files uncompressed, which is great for editing.
Setting up the Intensity can be a trial-and-error experience. It doesn't help that there aren't many support resources available on its website. You can contact customer support through email or by phone should you need to. There's also a forum where you can ask questions and help others resolve problems.
The Blackmagic Design Intensity can be a powerful game capture device, but it isn't designed specifically for that. Its emphasis on a broad range of video capture capabilities makes it somewhat difficult to work with. It isn't as intuitive as the other best game capture devices on the market. However, if you can get the Intensity to work well with your computer, then you'll be able to record and stream your games at a very high quality.