I've had both types of stoves/ovens and can tell you there should NEVER be a smell from the stove/oven when it's off. If you smell anything, shut it off at the switch and open some windows. While the stove/oven are in use, you might notice an odor during the burn/start but after a while one gets use to that at they go with an electric one.
Depending where the kitchen is located, one might want to consider having pocket/sliding doors installed, this would improve the chances to notice a leak (smell), they also could serve as a way to keep the heat in the kitchen as they (gas stoves/ovens) tend to run hotter than electric. Even with the doors closed while using, remember to keep the kitchen window open - yes, even in your winters.
If you have them for your renters, do yourself a favor and put an electric one in it's place (better to be safe than sorry). I had a place burn to the ground back in the 60's from a renter. Since then have made certain it's all electric. Learn from my mistake.