The Microshift derailleurs are pretty popular with the BoB crowd, and even a drool-worthy new custom Chapman was recently built up with a 10-spd Microshift RD with the logo polished out. It's a classic looking derailleur and apparently works really well according to the owner.

https://www.flickr.com/photos/chapma...7714810365741/

And let's be honest, the way technology trickles down over multiple generations of components, modern low-end components often work better than top of the line components several generations older. My Bike Friday cargo bike has one of the cheapest 8-speed Shimano derailleurs (I don't even know the model... Acera?), but it shifts better than my DA 7400 or my Shimano 105 RDs. I'm actually pretty psyched to try the Microshift on my daily rider. It's cheap, has the classic look, and supposedly performs great. If it doesn't, I'll only be out $38.