They are essentially the same pedals. DW renamed them to 3000 because of confusion. For a while, DW were making the 5000, 6000, 7000, 8000 and 9000 series. The 5000, 8000 and 9000 were the 'fully professional' ranges, the 7000 a 'mid' range and the 6000 were the 'lightweight' range - basically a version of the old 5000 pedal before they updated it.
The 8000 was a combination of the 5000 and the 9000 - the 9000 being the 'flagship' product. There was an issue in the naming because the 7000 had a higher number than at least one (and probably its most popular) 'professional' product. 2000 and 4000 had already been used so 3000 was the number that was free.
I hope that makes sense. Now the DW range is much less confusing.
2000, 3000 - Entry level/mid-level (4000 is no longer made, the 3000 is what used to be the 7000 but is the same pedal)
5000, 9000 - Professional (8000 is no longer made)
6000 - Lightweight.