I have used both generstions of EX1's. I might not be the best man to share detailed analysis, but you can try reading my earlier comment.
In short, the F9 Pro's are incredibly detailed, but to me it seems they provide a worse audio balance then EX1. Where they were balanced, but with still very great bass output. The F9 Pro's give that same good bass and even better clarity, and great clarity with highs too, but I found to be missing the great mids EX1 gave. But it makes it up at least for providing good isolation, to me it makes all the difference for outdoor use. But as for signature, I still prefer EX1 more balanced sound.
When I say EX1, I'm mostly referring to 2nd gen, but As far as I remember they sounded very similar to normal EX1. 2nd gen were slightly more bassy.