Yes. Any cryoed receptacle is likely to take as much as 30 days to really settle in. What you are hearing is normal. Bright, etched, thin, lots of detail.
If you really want to burn the receptacle in, take it right out of your system and replace the receptacle that your refrigerator or a chest freezer in the house runs on and plug the fridge/freezer into each half of the receptacle for about 2 weeks. The cycling on/off of the fridge/freezer and the large draw when the compressor kicks in will do more to burn the receptacle in than any amount of time in your system.
If you want the best out of your Porter Port, or any receptacle, that's the approach to take. After the month, stick the receptacle back in your system and enjoy. You will be shocked at how good it will sound. With a $5 adapter, this is also the best way to burn in power cords short of a cable cooker, even those that have been in systems for years.