Changes come faster for some guys and slower for others. I've only had one shot and been on T for 13 days and already my voice has dropped for the first time. But for some guys its takes at least a month for the voice to drop.
What I've noticed so far is that my junk is bigger, the voice, easier to build muscle, increased thirst/appetite, maybe faster metabolism, different orgasms, change in taste/smell...some other things...
If you think about it, the shot injects the T into our muscle so its like BAM...and stays there. The cream is only on the surface, so the changes won't be as pronounced. WIth the shot you'll most likely notice quicker changes.
Oh, and I'm on cyponiate.