The only one i have personal experience with is the elite set up on godzilla, only downfall i saw is its pretty messy to pull the engine because it basically drains the whole time, really not a big issue but thats the only thing i could maybe complain about. As always with external lines you run the risk of rubbing, heating ect where the hose might develop a leak and the bad part is you could pump all the oil out of the pan before you even knew you had an issue...
that being said even Cat uses external soft lines, seams to work just fine even in high abuse areas... only thing i think i would add is an external oil cooler to go with it.