I agree with the others. Not only makes printing easier and faster but also helps with the quallity. Expensive but worth every pence. I am sure the greyscale display goes hand in hand with the zone system.
Trust us, you'll have absolutely no regrets from buying it, except for the month the credit card bill comes in. It makes life so much easier, it will help pay for itself in saved paper, since you'll be able to get a good finished print within two or at most three prints.
With the Analyser Pro's densitometer function you can also use it to help find your personal film speed and development times. Great bit of kit, have not regretted buying one, even though it cost about the same as the rest of my darkroom equipment put together (mostly from ebay and excluding consumables)
I bought mine 2 months ago and no regrets my printing confidence has increased no end. You can get on with the printing rather than printing countless test strips and duff prints
It can help with the zone system because the timer works in stops - everything else done in photography works with stops so bringing this into the darkroom is a natural progression for me.