I've used Metroluxes (Metroluxi ?) since the very beginning. It is a great instrument and none is more repeatible or accurate. The remote sensor is most handy for me for resizing a print -- if I get a print all figured for times and then want to change the size. It can be used as a densitometer by a couple of means.
One is a projection desitometer where you can make densitometer reading with a projected negative. This is okay, but what you find out is how uneven your light source is. The better way to make densitometer reading is to use one spot of your light source, the center, and move the test negative over the spot. This eliminates errors due to the uneveness of light sources (they are all bad, its scary). I have also seen the remote sensor used as a densitometer on a light table where the remote sensor was converted to look down. This works pretty well.