I have Ausherman bars in my K2. Big improvement in beans, wheat and oats. I don't combine corn, but I'm sure there would be improvement there too. I have not used Trimpe bars yet, but I'm sure they will give you a lot more out of your F3.
I have a set of ausherman bars for an f3 if you are interested. they have a couple of hundred acres on them. I had just purchased the machine and was having problems threshing and blamed the bars, well come to find out I had other problems that was simple to fix and the bars were not the problem. I have experience with trempe and they are outstanding. these ausherman's may be as well but I did not give them a fair chance.