i think Ni gets bogged down easier, and Ne as an extroverted function is much more adept at adjusting external circumstances and envisioning MATERIAL solutions to potential problems. Ni foresees but has to use an effective judgment function to adequately see why it foresees what it does. to create structure. Fe is not exactly good at this.
intj gets pretty fucking tired of this feeling too, and i think even more so than anything else, it's just that it takes a lot of fucking energy to understand Ni and to turn it into something usable. it's so close-up that it has difficulty seeing how its inner workings relate to the external world in new ways/(that involve starting from scratch). whereas Ne always seems to be from scratch, totally NOW, vs the huge fucking immense bundle of perceptions that Ni carries around with it FOREVER.
intjs is more hierarchically organized so ready to get to work on a problem, its data and its relationships are more practically organized. but infjs is more hazy, fluid, fuzzy, floating/drifting. infj perceptions are so loosely and dreamily associated, indefinite, implicit, foggy and holistic. it takes a lot of context for us to pull the reigns tight and see something clearly, to focus the lens properly so that we see all related parts in perfect resolution. but it's very revealing when it does, sometimes for good and sometimes for bad, depending on how the actual situation fits with our often un-described and indeterminate desires.
Ni is drifting away from the world into an internal metaphysical system. we are trying to grasp relationships and connections based on our own imagination space, our ability to recognize and build/model that breaches the edges of our linguistic tools to make sense. it is our revision or our edition of ourselves. we are so focused as a result on a wider range of information from the past, and sometimes see far less information in the present. this makes us worry, and feel out of touch, and feel threatened by drastic changes that are new to us. bc we feel we need a greater mass of information before we are qualified to move forward (especially inj 5s).