Events can certainly be the place where new disciples are drawn in, but it's the people doing the discipling that make the biggest difference.
These folks are the most important component of the event and they must be equipped and released. What is the main thing these people are to be trained in? Evangelism.
Focus, as the book says, on training "people who can speak the good news both in personal conversations and in public settings..."
Here's an idea. Take the amount budgeted for any given event, increase it by 50% and then set that entire amount aside for training people. Should we be thinking this way?
What's your idea of the perfect event? Dynamic, motivating, and fun? Administratively flawless? Whatever comes to mind add this to it: Volunteers who are equally as engaging and energetic as the event itself; volunteers trained in practical evangelism. Their sole purpose at any given event is meeting new people and drawing in new disciples.
That would be a near perfect event. You would then be able to measure it's effectiveness by how many new relationships were made - emerging into other areas of church life.
This doesn't at all give us an excuse for lowsy events and programs. We need to draw them in somehow and not be a stumbling block in any way. But it's well trained, gospel speaking people, who make the long term difference.
These are just some thoughts as I've re-read The Trellis and The Vine.