Yeah, the PDX are supposed to be really good, but best of all they are small & stackable which give a lot more options for mounting locations. The only draw back i see to the marine versions are the sub amp is only 600wt and the 4 channel is only 100wt.

I just put a PDX 4.100 in my boat. Its actual test rating was 127 watts. I agree though that an actual "marine" amp is not necessary. The other good thing about the PDX's. They don't use nearly as much battery power and they do not get nearly as hot as standard class AB amp.

Are you running the Alpine 6.5" off of the 4.100? Did you notice any improvement in the sound quality over the other sub? Just curious. I am still going with the PDX regardless because of the other reasons we have both stated.

Thanks!

I'm using the PDX 4.100 to power 2 DC Gold 6x9's and 2 DC Gold 7's. They are 80w rms speakers. I started from scratch so I don't have a direct comparison.
I did have an RF amp at 70w x 4 powering 4 DC Gold(Babb) 6x9's in my last boat. The PDX will play louder and clearer up high, even with the gain set at 2/3.