We have had both.
Guini Pigs stink & are messy. The computer desk was right next to them & I sat there for a long time each day. My waist started to itch then after awhile I noticed spots. I went to my Dr. thinking maybe it was from my Lamictal but it was bites from some insect.
Hampsters were better (& smaller cage). One day my son called us at dinner to say there were finger sized things in the cage. You know what they were. She was pregnant when we got her & didn't know it. Later she had babies again cuz we kept the 'kids' (at least one boy) with her.