Well decided to order a couple more. Ordered 2 Rocks & 2 extra packs of coils, total shipped after %10 discount was $30.49. Figured it would not hurt to have some extra backups.
On rebuilding, after a while they do loosen up, and I think loose vacuum some, and start leaking. The 2 I was rebuilding I had rebuilt 1/2 dozen times each (or more), but now seem to be leaking into the coil area and flooding (could be a wick problem, but I don't think so). It's a slow leak, but after a few hours it is flooded and leaking inside the pod area of the Rock. So with the rebuilds I am getting 30+ tanks with my gunky juice, if I used a less gunky juice I would get more mileage out of them, but still that is not bad for a less than $4 for the pod & replacement coils.