Block work is necessary if you are a complete novice at starts, but honestly I feel like they detract from my accel sessions because I end up freezing from thinking too much. If you have someone with you able to call the starts its a lot better, but if you are by yourself they tend to hurt more than help me.
I do tons of start work, ie: medball accells, starts from mutliple positions (falling, on stomach, pushup, etc) along with hill sprints. I usually only do blocks once a week for only a few starts.
I disagree, novice should stay away from blocks even more and put more focus on the other start components.