how many of you guys use line levels as opposed to the laser sights that beep when you are at the right level? how hard are they to use? i saw them demonstrated at mahts last year and am thinking about getting one as my business grows. i don't ever do jobs over 3000 sq. ft and most are about 1000 sq ft. or less. also what other big tools like paver carts etc. do you guys find worth the money. i'd like to hear your thoughts.