Sometimes it may take a little time to upload videos. Typically, you will face such issues during times of peak traffic. I am just about to upload a 9 minute video, and it took me a good one hour to upload it. Basically, there are queues for creating Sprite and Encoding which take long after an upload. Don't worry. You should be able to upload your videos soon enough. But yes, on an average, DTube uploads are slower than YouTube uploads. Hopefully, the devs will fix it in the coming updates.