What's your speedtest.net score? I did a bit of digging to see how evolved this has become. To go into more detail:
Your bandwidth will factor into the quality of your stream. The UFC.tv app will automatically detect your speed and adjust the stream quality. The bitrate can't be high, but I believe the highest end streams are 720p@30fps. UFC.com offers a conflicting report of their maximum bandwidth on their website:
http://www.ufc.com/ufc-tv-help
The conflict is that the first quote says 3MB, and that would suggest 3 mega
bytes per second. The data rate in the second quote, which appears to be reporting it more precisely, and is therefore likely the accurate one, says 3.0Mbps, and that indicates 3 mega
bits per second. This is much less data. For reference, 3MB/s would equal 24Mb/s. Speedtest.net reports your score in mega
bits. If your average is at or above 3.0Mbps, then you will receive the highest quality via the app. It simply isn't conceivable that they're broadcasting a truly high bitrate 1080p image at 60 frames per second with this much data. This data rate would support, at best, a 720p image at 30 frames per second with a modest bitrate. This means the image will be less crisp, less smooth, and will suffer probably sometimes pixelate.
This is probably why they charge (I believe) $44.99 for a UFC app stream versus a traditional PPV buy of $59.99. So let me renege on my former recommendation based on VG forum anecdote. If you want to show the best image with your new TV, then order the traditional PPV.