None of my original training dive logs were signed, we were told it didn't matter once you get the card. As you have seen, most here agree with that logic. Logging your first 100 dives, either electronically or on paper, makes sense for the new diver. Beyond that electronic is the only efficient option. I recommend logging until you get everything worked out for the diving you intend to do. If you change wetsuit thickness or to drysuit and back, or salt to freshwater than you will rely on those logbook notes to keep your weighting in order. Once you get your own kit then you will inherently know your weighting based on the kit used, i.e. warm vs cold or salt vs fresh. I keep a card in my save a dive kit that has different weighting for different diving and only log dives with my DC.