I prefer ink pads over markers for watercoloring with ink, in general. When I watercolor I find it easier to work from a palette rather than coloring and blending directly on the paper The ink pads are easy to tap onto an acrylic block for a quick palette. Blending with a regular paintbrush or waterbrush is often more effective than trying to blend ink out from a colored area - not all watercolor papers are equal, and some will hold the ink instead of allowing it to move and blend. Ink pads are also easier to apply to a craft sheet for Wrinkle-Free Distress backgrounds
. These techniques are a great way to stretch the use of your ink pads, beyond traditional stamping. Markers can be great for 'direct to rubber' coloring where more than one color is needed, so that is one thing to consider. I prefer the 'real brush' markers to felt markers, which can tend to fray or smell over time.