Like Mike's, my Bestop safari top has both a velcro sport bar attatchment, and runners for attatching to a door surround. Before I bought a soft top and door surrounds, I just used the velcro. Works fine, until it rained. Then water poured on the inside of the doors.
Now with the surrounds holding the Safari top, it is much tighter, and I stay dry if it rains.....that is assuming I have my full doors with me!