F2 was short run and underpowered, guns-wise. It had a 15mm with the same ammo count as our current F4 has, but had engine problems and teething problems.
I don't see why everybody's arguing for an F-4 without gondies -- they seriously inhibit your fighting ability, so it's a trade-off, you pay for the firepower with severe performance loss. To me, I see that as a fair trade.