So I just had my secondary cats removed and put an xpipe hoping for a nicer-louder v8 sound but to my disappointment it did the opposite! it got quieter! before with just the resonator delete it sounded so much better. Is this normal?

I'll be putting the cats back on Thursday.

 

The x-pipe can be quiter than straight or H-pipes. But I don't think it will be quiter than 2nd cats delete.
My advice is to drive the car for a while as the sound will change a bit. If it doesn't improve much, install an H-pipe and see how it sounds.

 

This is strictly my personal opinion - but nothing sounds better than stock on this car. Sure, long tubes and maybe a few thousand at a decent set of mufflers might make it better/more pronounced, but stock exhaust, to me, is perfect for this car. Throwing a simple pair of C63 mufflers I might be OK with, even that takes away from the factory perfection sound.

Just my .02

EDIT: Just noticed you drive an E63 and not an E55.