After about a month of use, I decided to return Surface Pro 4. I had i5, 8GB RAM, 256 GB SSD version. It was plenty fast but not significantly faster than my 5 years old laptop. But performance was not my main concern. It was lack of lap-ability, the reason for returning it.
I wanted to make it my main laptop but it was not always comfortable in lap. Cannot use it easily with one leg on knee. It was not easy to use in bed. It needs a keyboard like Surface Book for it to be a full laptop replacement. For now, I will wait and see what happens with Surface Pro 5. Perhaps, I will get Dell XPS 13.
After returning Surface Pro, I missed drawing on it a lot. I was bumped until I discovered Wacom Intous tablets (Affiliate Link). These tablets let you draw on computer and cost less than a $100. I will be using it for my T-Shirt design ideas.