Every seal can be overcome by enough crap; the best advice if you're going to play in the mud is to get components whose bearings can be easily and cheaply replaced. That does put hubs with common cartridge bearings in first place, but that's easy for Pompetaministas to say, there is plenty of choice at 135mm OLN. At 120mm, it's a bit harder to find a freewheel/hub combo which jumps through the hoops quite so effortlessly.
Every seal can be overcome by enough crap; the best advice if you're going to play in the mud is to get components whose bearings can be easily and cheaply replaced. That does put hubs with common cartridge bearings in first place, but that's easy for Pompetaministas to say, there is plenty of choice at 135mm OLN. At 120mm, it's a bit harder to find a freewheel/hub combo which jumps through the hoops quite so effortlessly.