Mine is driving me bonkers, so I'm looking to see what else is out there. I'm using one of these:

Apart from just breaking PLA on seemingly random occasions, I have also had to completely disassemble it and rebuild it every time I've needed to either feed new filament or re-feed filament after it has broken. Getting the filament through the pulley/drive gear is easy enough, and up into the hole, but from there it just refuses to enter the bowden tube.

What're your favorite alternative designs?