I have used disks and screens and have somewhat mixed reactions about the disks. As you may know, disks are designed and intended to be used primarily with air impingement and other types of conveyor ovens, so they are not a natural fit for deck ovens (and less so for home ovens) even though I am sure that there are pizza operators out there somewhere who are using them in deck ovens just as they are using screens in such ovens.
In terms of performance, and especially crust browning, I have found that I can get better bottom crust browning with a screen unless I put a light coating of oil on the disk before putting the skin onto it. My disks are all perforated so I have to be careful that I don't put too much oil on them such that it escapes through the holes onto my oven's lower heating element. Also, in my oven (a conventional electric oven), it takes longer for the pizza to bake on a disk than on a screen. I believe that is because the disk has to get up to temperature first before the pizza can start to bake. If the total bake time is too long, especially if the oven temperature is on the high side (above, say, 475° F), that can be bad because the cheeses might not hold up well to the long bake and break down and give up the fat, which can manifest itself by a puddle of oil on the pizza. Also, a topping like pepperoni can also overbake and release fats onto the pizza, with the pepperoni becoming dry and rubbery. The oils in my case have had an orange color. I don't have ready access to Grande mozzarella cheeses but I would use them if I did because my experience is that the Grande cheeses hold up well to long bakes at high temperatures.
I have also found that I don't get as good an oven spring as with a screen unless I allow the skin to proof on the disk for a while before dressing it. Apparently in my oven the disk doesn't achieve a high enough initial temperature fast enough to induce greater oven spring. In my case, I have preheated the oven only for so long as to achieve about 500° F (ambient temperature). That preheat time is usually about 12-15 minutes. I have refrained for the most part using the disk with a stone because that would mean a much longer preheat time (about an hour), which I would like to avoid during the summer. My goal is to have a disk be a substitute for a screen in a minimally preheated oven.
I might add that my results have been pretty much the same even when I have tried the new hearth-style disk that is intended to produce results (in a conveyor oven) that replicate a NY style pizza baked in a deck oven. I know that member MWTC has been very happy with that disk, used either alone or with a pizza stone, although I believe his dough formulation is not a NY style. Also, I don't recall what kind of oven he is using and whether he allows the skin to proof on the disk before dressing and baking. Most of my experiments using disks have been with respect to a thin, NY style dough containing no sugar. In MWTC's case, he is using his hearth-style disk with a dough formulation that includes honey, malted milk and dried dairy whey. Those ingredients should help provide more browning of the crust and quite possibly provide a better match between his disk, his particular dough formulation, and his oven.
It's possible that I haven't done enough experiments with disks so I don't want to discourage you from getting a disk and experimenting with it yourself. With the right dough formulation and with the right oven, you might get very good results, just as MWTC has apparently achieved using the new hearth-style disk. If you decide to try a disk, I would recommend getting a dark, anodized one, such as sold by pizzatools.com and American Metalcraft. As you may have already discovered, disks are considerably more expensive than screens, by several multiples.