The whole varying viscosity is a useful deal and have different properties and uses I find. For instance I use JetGlu instant jet when adding "spot welds" for lack of a better term to joints that need extra support once pinned and glued during assembly. It also has the added benefit of flowing like water over surfaces and down along joints and corners via capillary action, something impossible with thicker more viscous glues. In addition it doesn't obscure details when it dries. However needing to perform the initial gluing I like slow drying thick glue (in my case Slowjet) as I can make adjustments to get it correctly seated or correct mistakes made when initially placing it. For example, I can glue a strip stand of infantry to the base and go, "you know what? I want to turn that guy to the right and swap the two guys on the ends" and can without any trouble.
like all things YMMV and what one person likes another well may detest. I've been using glues like that since the 80's and could not imagine living without them. You probably would not imagine living with them.
Regardless, do go with a high quality glue for your hard worked on projects. Nothing worse.than having glue fail on something you've worked so hard on. Real life example: I have an original Captial Imperialis from 1st edition (what is that? 1991?). It has survived dozens of moves, some across continents, and plenty of man handling. Other items of similar size I've had literally fall apart in a game from poor quality glues (in this case GW super-crap).