Using a graphics tablet to support recorded lectures?
My personal experience with different media used during lectures (basic calculations during an engineering course)

Tablet:

I experimented with my tablet (Galaxy tab S) but to be honest, my handwritten notes look like a child had written them. The Galaxy S is not particularly designed for taking handwritten notes, so maybe other tablets are suited better.
Graphic tablets from Wacom may be suited well. The possibility to project the notes live while explaining something to a particular group anywhere in the classroom may be a big advantage but in my opinion it does not outweigh the unprofessional look. Unfortunately, no shop in my town has Wacom tablets in stock. Otherwise I would try them. One of my students uses the new tablet-laptop from microsoft and is very satisfied with his handwritten notes. Still, the writing looks not very professional.

Document camera:

There are different models and I used a document camera in the price range of 700 $. The camera itself can be used to capture the notes while writing on a notebook. The video can be streamed live using standard video software. Additionally, it is possible to record the session and save the data on a SD card (including your voice). I like the feeling of a pen on paper and my notes look much better than on a tables. In my opinion it is the easiest solution right now.

But nothing beats the white or chalkboard. The possibility to teach while using my whole body for supporting the things I said is most comfortable for me. Furthermore, there is no device or desk between me and the students. As a consequence, it is easier to focus their attention.

Since most questions do occur every year again and again, I produce short videos at home using my hq-webcam. It is much easier for me because I can focus on one particular goal (producing a video, or explaining something to one student in one particular class). I am not the multitasking type.

To sum it up:
If you like the feeling of a pen on a paper you might want to search for "document camera"

You may want to look at those two videos:
Tablet for Tutoring Wacom Pad in Teaching