I'll give it a try. I'm not a reviewer, can't talk PraTT, or plankton for that matter. Also, it's been my experience that Grado's can be driven very easily, but I've noticed that they scale up very well. My system of Yggy + GS2 and V222 SS or Feliks Audio Espressivio has really transformed both hp's for the better. As always, YMMV!!!
That being said, the 325x has great bass extension, while still reflecting the Grado house sound. However, differences between it and the 30000x are quite substantial. The 3000x as compared to the 325x
1) Much larger sound stage which also reflects the air between instruments. Not close in my opinion
2) Much better Timbre - Fully balanced sound from bass to mids to treble. Everything just sounds so right. Smooth, no "grit" that some may notice and appreciate with the 325x
3) Tighter, more punchy bass, but doesn't get quite as deep as the 325x
Now, you might think that given the substantial differences I noted above that I would be selling my hemps, 325x, and RS1x. I'm not going to anytime soon!!! Although I believe the 3000x is technically superior to the other headphones, and at least in my mind sounds substantially better, I love the others and change things up often. When I do, I find a reminder why I like the 325x and the others. Different flavors for different moods.
If I was rating this review, I would give it about a 4.5 out of 10. Sorry I can't be of more assistance. Regardless, enjoy your Grado's and listen to the music!
Leo