sediment is a sign of a live beer, and will result in a small loss of beer when pouring to keep the sediment out of the glass. you can minimise the sediment by standing in the primary bucket a little longer and even moving to a cold spot a day or 3 in advance of bottling as the cold will encourage the sediment to drop out, those of us lucky enough to use fermentation fridges or other temp controlled methods regularly crash cool the beer to clear it at the end of primary. the cold wont harm the yeast just send it dormant and if in bottles will soon warm back upto conditioning temps.. And even if you bottle the clearest britest beer you will still get sediment as a result of the natural conditioning.. to bottle brite clear sediment free beer investment into a keg and a cold counter pressure bottling system is the best but expensive option, some bottle from a pressure barrel but the shelf life of pb bottled beer isnt the longest, ok for a few weeks, and the degree of condition isnt as high as can be achieved with bottle conditioning or counterpressur filling.
Kit instructions do tend to err on the shorter side of recomended time lengths, it helps sell the idea of hombrew to the uninitiated.
