Of course I used it.
After all, is there anything better than tearing through the Elite Four with a Magikarp?
Tearing through the Elite 4 with a Wobbufet?
Actually, being a kid in a small town when I was younger, I didn't know much about cheats. We at my town just played the game. A lot of Kids used Charizards, and one kid found a cloning Glitch in G/S. We made fun of him because of that. He had a team of Legendaries. Ah, the early Ubers of my life... One of my friends eventually beat him, making him Teh Best Trainer EVAR. In a couple of months I beat him, and I got beaten by a friend. The circle still goes on, even today.
Personally, as I grew up in a small town, I preferred THAT over the cheating and whatnot. It made the game much funner and more eventful. My hometown was small - If one kid had a cheating device, they all would. That never happened, though. At least, not until the R/S Era. Even then, the few kids who used it were bashed, though the ones who did the bashing eventually obtained the cheating devices themselves.
The game eventually became boring. I never cheated myself, because I was one of the few still having fun. Kids quit, and the card game fanatics began.
That was around the time that I left my hometown.
Cheating devices were used, yes, and it made the game boring. I never used them myself, though a lot of others did. Just not during the G/S/C era.