Get the longest one that you can.
I have had the Miner (Miss it badly)
I currently have the standard Prospector (wish it was longer)
You get a longer deck to help break the material up more so it doesn't just clump into the trap.
You also get a wider front flare, more water, better fluid bed activity.
The ONLY thing that I did not like about the miner was not being able to clean out into a bucket, that's the ONLY thing that I didn't like about it.