With waterproofing, it's really an "all or nothing" scenario. It's dry or it's wet. They worked for me. The only caution is that that the connection wire must be clipped a bit short my comfort so I also used the shrink tube as a precaution.
I have used other brands, and found that they did not seal as advertised. These Ancor connectors work very well - and seal evenly every time. They also don't seem to require as much heat as some others.
These things do not shrink down to fit snugly even when a lot of heat is applied, thus are not water-tight and not weather resistant. The regular heat-shrink tubing works much better in my opinion, and it's quite a bit cheaper.