Would you Prefer to render the drawings with hand sketching & coloring or by 3D Program, and why ?

I would prefer hand rendering. 

I prefer to manual render  once in a while  the conceptualizations  and 3d program for final presentation

I can use both of them, but it all depends on what client he wants

Prefer to play with 3D Softwares. And it will almost give the desired output.

Rendering the drawings with hand sketching & coloring has been my hobby before I was able to use any 3D software, as it reflects your personality as a designer and is the initial step to start off with any design before it can further be developed.

However, when I started to learn 3D programs such as SketchUp and 3Ds Max with suitable Plug-Ins, I figured it was much faster and easier to visualize and design the space. It gives more chances to experiment what's suitable within the space in terms of lighting, texture, materials, etc. 

In my opinion, 3D rendering program is an easier and faster way to visualize and design a better space. 

To draw all you really need is a pencil or pen and a scrap of paper.If you have that, skip this section and start drawing.However, if you don’t know a darned thing about drawing materials, what they look like or what they do, or if you need encouragement, understanding, wit, or just like to look at art stuff, read everything on this website. It’s free.The choices available in drawing materials are wide and varied. The links at the top of this tabbed page offer examples of the conventional drawing media that artists choose to work with. Some drawing media such as pastels, or ink and wash, require much further study in color technique and approach even after you learn to draw well.For any drawing lessons or examples I will generally use graphite pencil on paper unless I am showing the working properties of other media such as charcoal or crayon.It is best to learn to draw with simple pencil and paper. Some of the world’s most beautiful and famous artworks are simple pencil and paper. And it is a very cost-effective way to start becoming the artist you intend to be.

I prefer sketching ideas on paper first before importing it into a Cad program

I personally prefer hand sketching since t reflects a kind of personal unique identity through the style by hand. 

the drawings with hand sketching & coloring

Manual drawings and sketching is more preferable for initial design phases but software rendering is much reliable for project presentations.