There's a guy on Youtube named Bijan Bowen who tests all the models (open and frontier) on a series of one/few shot programming exercises and has been for a long while now. You can pretty much watch him compare the results for any two models you're likely to be interested in.

I'm not affiliated, I just like his style and have found it handy. I know it's not very rigorous, but it's good enough for me and I've found his examples to pretty closely match the results I see in real life.