Hey Cassin... well, I have been on it for a month and a half, maybe two? I'm well into my second cannister.
It is hard for me to comment on the results, as I went on it after dropping Xandrox 15. The thing I can say is that I have not lost anything after dropping the Xandrox, thank God. So, the slow regrowth and definite maintenance seems to continue and the Xandrox-inspired shoots are still germinating, a good thing!
The one thing I can say is that it is a bit hard on the scalp. I know that you, as well as I, are believers in the concept of absorbtion maximization and I think this formulation is in line with that concept. It feels great after application, cumulatively over weeks it tends to start to sting. Nothing painful or particularly irritative to me, but my scalp seems to be like leather and rarely has ever gotten seriously irritated, at least since I have been taking the medicatives to calm it.
I know you have had some scalp sensitivity historically, I would try it for two months to make sure it is compatible with you before making the big purchase. It definitely packs more zing than the ol' #500, so perhaps a testing period might be good?
That being said, I only use the Retin-a version at night. In the am, I use the standard #500 formulation. The retin-a version has the same application characteristics as the #500, it's a bit drippy, dries quickly, but has a slightly more amber hue to it.