Our Troop had a "Venture Patrol" but initially the only thing different about it was that it was for Star / Life / Eagle scouts. When it grew to 24 boys in '96, the "standing around bored at meetings" syndrome was reaching critical mass. Being the world's second oldest teenager, I got along great with this group and asked the Scoutmaster if I could start doing a "Venture only" program. "Whaddyayoukiddingme? Go do it!" was the response. We started doing our own thing: backpacking, rafting, Appalachian Wilderness Adventure, and wore red berets in parades, etc. The envy in the other patrols was huge, and many stayed in just to get into Venture.
When Venturing started, this became our core group for the Crew. We moved the Crew meetings to a different night than the Troop meetings, and the sisters of the guys in the Troop (who were hanging around at Troop meetings anyway) joined.
We're on our third generation of Venturers in C116 - the original group graduated out, as did their younger sisters & brothers.
Until Scoutmasters really understand that Venturing does the opposite of "stealing their boys", I think there's still a place for Venture Patrols.
YIV,
Bob