Is a "lecturer" position sufficient for a career and not a temporary position? Can it ever be useful if not intended as permanent?
The context here is clearly the US system.  I'm responding based on my own experience working with people in such positions at my institution and elsewhere.    

This is ultimately a personal decision.  There are certainly many institutions where instructors have been employed for decades and even reached retirement.  Having a stable job is better than having an unstable job or no job at all.  

However, 


Lecturer/instructor positions are not generally tenure-track positions.  You won't have the protections of tenure, and if your institution comes on hard times, you'll be one of the first to be laid off.  
Although some institutions have "senior" instructor or lecturer job titles, there isn't nearly the same scope for advancement as for a tenure-track faculty member.  In particular, tenure-track faculty can advance from assistant to associate to full professor and ultimately into department chairmanship or higher administration.  In terms of salary, you're likely to be stuck at a level below the tenure-track assistant professors for the rest of your career.
Instructor/lecturers seldom get to teach any but the lowest level (remedial, developmental, and first year) courses.  You probably won't have the opportunity to teach advanced undergraduate or graduate courses.
You may not have much control over the syllabus, textbooks, etc.
Teaching loads can be very high in these positions.  There just won't be time for any professional development.  
Taking one of these positions for a year or two might help your chances of getting a tenure-track position at a teaching-oriented institution (because you'll have gained some teaching experience to balance with your research background), but after you've stayed in such a position for a while (say five years), your chances of being able to move into a tenure-track position at even a teaching focused institution will decrease substantially (because at that point your research will have stopped, and even teaching-oriented institutions want some research from tenure-track faculty.)  


In short, it's a deprofessionalized dead-end job.