Well I beat floor 50 and I'm only 14/15 on my gear. There were NO silver chests at all in that 41-50 climb (well, there was one but it exploded so it doesn't really count.) Unfortunately given the incredible annoyance of RNG, combined with the fact that you have to do the lower floors over and over again for minimal reward, I see myself getting bored with this VERY quickly.
I just wish the lower floors did SOMETHING at higher gear levels. Even if they just made the bosses drop a chest with guaranteed upgrade. At least then I wouldn't feel like I'm just wasting my time.