For sure it would bring more traffic. Also, usually, conversions should improve. But CPC will increase - so it depends how much can you afford to pay for an action. Just test for a week and watch carefully the results.
First of all, a better position will bring more traffic - so more actions (sales, subscriptions). Second, usually, the conversion rate increases when you have a better position (but you have to test!). This means that from 100 clicks you will have more subscriptions on pos 2 than on pos 5. However, the CPC is also very important!
my strategy is being second. being second is much cheaper in my market and I compensate in highly attractive ads. I tried being first and it didn't bring enough traffic to make it worth. The 3rd is not so good. When you're 3rd you are really loosing lots of traffic.
I know this flies in the face of common wisdom, but my conversion rate is actually higher around positon 5-6. I don't try to be 1-3 because I've found that many people will visit the top sites, click back and visit a few down the list. You get more "tire kickers" and "click fraudsters" in the higher positions. I've found that I just waste money at the higher levels.