It's not better or worse, but rather "different."
Thicker strings are a bit more compressed than thinner ones, which gives you a "darker" sound (as the attack is less pronounced). for some situations that's good, for others, less so. A strat, for example, should never have anything lighter than 10's on it, I feel - especially with a maple board, it's a very snappy, "attack" driven tone, and really the whole point of thw guitar is that explosiveness. You want to be able to put some weight into your picking hand to play up the bend, rake, and scream aspect of the strat tone, as well as tame the presence a little, and thicker strings kick ass for this.
For a basswood bodied 7 with a rosewood board... Eh, honestly it'd probably make more sense for me to be playing lighter strings than I do, but I've found that I tend to phrase better on heavier strings, where I have to fight a little more. So, for me, it's worth it.
