Could I downgrade my iPhone 4s to ios 7?

If I needed to? I'm thinking about updating to ios 8.0.2 because apparently it runs better on the iPhone 4s than ios 8.0.1 does, however if it turns out it slows down my phone too much ect could I downgrade back to ios 7, or would it be difficult/not possible? Is it worth upgrading?

Right now yes. They are still signing 7.1.2 so you could restore to 7.1.2. Probably won't be signing both for to long though so you would have to revert to 7.1.2 in the next couple of days. Also you will have to download 7.1.2 and you will have to hit your shift key when you hit Restore in Itunes so you can select 7.1.2.

Its not possible to downgrade and I think you should give it a try upgrading your 4s to 8.0.2

Ios 8 on a 4s will slow down your iphone and it is too late to downgrade. To do so you would need to downgrade just 2-3 days after the new os comes out. Ios 8 is very nice but 7 is good to. You have a older model and it my lag a lot I say leave it for now.