I think, combining both methods, -- software ( like LR) and physical presentation ( like using flashcards, manipulative, touch and feel lessons), -- would bring the best results, as baby is using all different senses to absorb the information and it comes in variety of ways. Interaction is extremely important! Even when my little girl watching an educational video, I still trying to interact and repeat things together, point things out, pose video for a minute to ask a question, etc. And in LR it comes naturally

And also when we do some hands on activities, like earning letters with wooden alphabet blocks for example, I like to add a few minutes of some multimedia at times for variety, so I can put an alphabet video for her, or a song about letters, etc. In other words, for us it works best when we are combining different methods, as it brings variety in.