Im not sure buddy!
This is the newer fox and I gave it a little test on my buddies bike, it was smooth.
Even thought it was way to soft for me, it didn't bottom out on the little 60cm drops I was bunny hopping.
I currently have a monarch on my bike and love it.
Its plush yet ramps up the way I like so if you like your pearl, just keep riding it.
The only time we really need to change or upgrade parts is when you notice something a bit odd to your liking or proper functioning.
My personal experience with a DHX5 is not good.
I have had 2, one a coil over from 2006 and the other the DHX5air from 2010.
Both rode good but always felt too stiff for me.
YET, they would both bottom out harshly off of a drop no more than 40cm.
I never figured it out other than I think their propedal was a flaw.
It kept each pedal stroke feeling strong with little bobbing so it was awesome.
But in rocky sections it felt stiff and not as plush as I would have liked but it had no back bone and once the propedal was opened it would bottom with harsh clank!
But, if you have it ready to go, its worth a ride.
Test it out and see how you like it.
If you don't do a lot of jumps or drops you might find it better than the pearl.
Or if its a newer DHX5 the problems I had may be gone in your shock!
But I think I´m drunken...I see so many waves