Golden Retriever
Pros:
It was designed specifically to grab and hold a disc.
It works most of the time.
It folds up into a nice flat shape that fits in your bag and you never even have to think about it.
It has a very long range depending how much string you put on it.
It can go over high fences. I've used it at TPCC to get a disc from over a 12' deer fence.
You don't have to see your disc to get it. Just blind dragging works sometimes.
Cons:
You have to unwind the string and then wind it up every time you use it.
It sometimes won't work if there is tall grass, roots, weeds, or too many rocks around your disc.
It does not really work for discs stuck in trees but isn't that what rocks are for?
Sceptor
Pros:
It works in tall grass, weeds, etc where the retriever might not work.
No string to unwind or wind up.
It can be used for discs stuck in trees as well as water.
Cons:
It's not small enough to fit in your bag out of sight out of mind.
It has a limitited distance.
You pretty much have to see your disc to get it. Blind dragging would be a nightmare with a sceptor.
It pretty much does the same thing a stick will do. Just find a stick.
Fatmax
Pros:
Fits in your bag but not as flat as a retriever.
Works for water and trees.
Has a good distance potential (35').
Cons:
Is difficult to use on a windy day because it's not rigid enough.
It's kind of a heavy weight to add to your bag.
water retrieval is limited for a couple of reasons mainly due to rigidity issues.