For regular data use (all except video streaming), both Play more and Do more have the same speeds when using premium LTE data
Play has 25 GB premium LTE data, and Do has 50 GB premium LTE data
After premium LTE data is used up, both may be slowed depending on how busy the network is and be prioritized below those that still have premium data. But the speeds would be the same - just can't say what the speed will be as it depends on the network load. Could be exactly the same as premium LTE speeds if network use is light, or it could be less than 1 mbps if network is in heavy use.
Watching video is different. Play will deliver speeds to allow 720p video, but Do will only deliver speeds for video to allow 480p video.