Third the Pendraken! And I say this despite having 15mm FPW Prussian and French from Outpost and Freikorps respectively. I bought some samples of the Essex when they first came out, but to my tastes they seemed a bit too…hobbity. Torsos seemed too large if memory serves, so the proportions looked off. To me anyway. I’m sure once they were painted up, they would look quite nice.
Freikorps (well, QRF now) are closer to true 15mm, but I love their FPW cavalry especially. The Outpost are good, although a trifle thin and taller than my Freikorps.
Still, I’m much happier with my 10mm armies of the period from Pendraken.