Once established, it is a weed. In a high-light environment, I have some 36"+ stems trailing the surface. It is not a prolific brancher. IME, if you top it, the top portion tends to rot with a few side shots forming lower down the stem. I also find it prone to melting when re-planting or moving between the tanks. The bottom of part of the plant melt but with the tips continuing to grow.
The picture below is somewhat unusual for me as it only gets that color right under very intensive light. Otherwise, it mostly stay green with dark burgundy stem. I'll try to take some pictures of the 'normal' form.