Here's how I see it (having learned on stock, but used Original for a few weeks):
Original:
+ Turn equal distance to jump from either side, making jumps on your left take less time than with stock
+ Easier to aim rockets, as they come out of the center
+ Can spam around left corners easier than with Stock
+ Quieter, can't hear rockets fired from it as easily
- Takes longer to jump on your right since you have to turn further
- You might be less effective with DH (if you decide it'd be useful for something), and if loadouts go down
- Cannot spam around the right of a corner as easily
Stock:
+ Jump faster with jumps on right side
+ Spams around right corners much easier
+ More consistent with no loadout/DH
- Jumps slower from left (you have to turn further)
- Can't spam as effectively around left corners
So looking at these pros and cons, the only real advantage the original seems to have is being more consistent w/ jumps or spamming with respect to which side you're on (which is balanced out by the stock having much better results on one side, but worse results on the other), and being easier to aim (which, if you spend enough time with the stock RL, is completely negated since you can aim it just fine after you get used to it), and the fact that it's quieter. However I find it VERY useful to be able to corner-spam with the stock RL, something you can do much better with it than with the original. It's also nice to have stock for when items go down.
In the end, I think it's really just personal preference, but I think the stock might be slightly better.