@gollum,
I would.
The Roku would probably give you greater benefits. You can get all sorts of stuff through a Roku. And if you already have cable or satellite service, most of your major channels will consider your existing service as authorization to stream on demand through your Roku.
Unless you need one of the boxier models either for compatibility with an older TV or for more advanced features, I'd look into getting one of the Roku "sticks". A Roku "stick" looks something like an enlarged USB memory stick and plugs directly into one HDMI and one USB port (for power) in the back of your TV, with the wire between the two ports doubling as the wireless antenna. It's all very tidy and out of the way behind your TV.
On the other hand, if for some reason "what you want to watch" is not available over a streaming service, a DVR would be able to record it. So there could be a few situations where a DVR is preferable.
Plus with a DVR usually you have your recordings until you erase them. A streaming service might only have the last four or five episodes of a show, depending on what the service provider chooses to offer.