I'm currently Publishing with Smashwords, and just heard about Draft2digital

I'm very happy with Smashwords, but they only pay quarterly, and that has always been a problem for me. I just heard about a self-publishing platform that pays monthly, a site called Draft2digital. So I signed up, a process that was an easy, one-page, step.
I love Smashwords, despite the only paying quarterly thing, so I don't intend to delist my books from them. I think it'll be a good ieda to put my books on both platforms, so I can really compare the two services, side-by-side.
Then I decided to upload my first sci-fi book, Galaxy Dog, to see how simple that process was. It was, as many people have commented, much easier than the Smashwords process. Soon the book was available at a site called Inktera.
When you are creating your book, they also have a nice feature where you can offer readers the opportunity to sign up to get notification of any new books you publish.
Once you have created your digital book, Draft2digital then prompts you to create a paperback version, which is great because I would otherwise probably not get round to it.

The first time I tried to publish my paperback, I got an internal server error. So I trimmed the cover image that the site provides and tried again. Same problem. Then I realised that the template was a little tricky to understand. They provide red lines within the template file, but not in the right places, in a strange shrunken box. (In the image you can see how I had to upscale the guides). It was the first tricky bit in their setup, and a part that could use improvement.

I am using Blender to generate the front and back covers, and each had to be huge, at 2800 x 4000 pix. It was a little difficult, but once that was done I figured everything would go smoothly. So I tried again with another png, this time the right size. Server Error. Then I tried with a jpg (even though the template is a png). Then I tried a PDF, and I finally got an error message, where I was told to keep the file below 40MB. Which is strange because the file I was trying to upload was only 24MB. In the end I gave up and wrote an email to their support.