I've been using either Adapalene or Tretinoin for about 3 years now.
I started off using 0.1 every night (go big or go home). Suffered badly with shedding and irritation/soreness.
Dermatologists seem to recommend using the weaker strength a couple of times a week initially, then gradually building up to once every night. Then after a year, you can reduce application back to a couple of times a week where you should yield the same results.
Microgel is my personal favourite, but it's really important to find a simple skincare routine that incorporates a good moisturiser and sunscreen (which I still haven't found as every sunscreen seems to break me out).
Regarding facial rejuvenation, I haven't seen any big improvements, nor have I seen any changes to my hairline. I've now incorporated azelaic acid into my daytime routine.