A buddy rolled my '94 with an all pro cage with the sleeves. It was a full, good roll and they didn't budge at all. The top of the cab wraped around the cage to the point of seeing the outline of the cage clearly in the sheetmetal. I would not hesitate to use the sleeves again, at all. One good thing to do though is make really fat floor plates that go up the firewall and sandwhich plates for the bottom that are a different size so they can't sheer the metal. I even made my rear hoop plates mount through the bottom and back of the cab just to create some extra rigidity.
The only problem I can see with the tube connectors is that it will be hard to get you padding around them. If you can figure that out I guess they would work just fine as long as your welds are good. I know they make some other types of fasteners for this same problem. If you search around on off road fab sites I'm sure you could find a cleaner method than the sleeves. I've seen these connectors with two halves that bolt together and kind of press into the tube joint ends.
