As far as mindfulness meditation itself is concerned, the Sahaja Yoga Meditation (SYM) approach has some important similarities to mindfulness, in that it also emphasises awareness of the present moment and the idea of disengaging attentional processes from the flow of internal and external events (rather than reduction of physiological arousal). A critical difference however is that this state of “present moment awareness/passive observation” constitutes only the prelude to a more important and specific experience of mental silence — nirvichara Samadhi. Thus while SYM is a specific experience that can be preceded, if not facilitated by present-moment observation and other mindfulness methods, the sine qua non feature — elimination of thought activity — distinguishes it from mindfulness meditation.
You can find information about the implications of the similarities and differences between mindfulness-oriented meditation and mental silence based meditation at Dr Ramesh Manocha’s blog.