planar magnetic vs dynamic driver headphones

due to my living situation , townhouse i tend to listen to headphone more and more.
my absolute favorites are my OPPO PM3's where are the planar magnetic design.

i also have a pair of HIFIMAN-HE 300's with along with my Grado 60's both are dynamic driver type and i enjoy them as well. i also have a pair of B&W bluetooth headphones and use them wired with my laptop.

my set ups are 1. macbook pro-Audioengine D1 with an audioquest jitterbug and audioquest cables
and 2. my stereo which uses a Cambridge AZUR 540A amp , and a JDS labs ATOM headphone amp , it also has
a iStreamer DAC when i use my iPhone for listening.

i have been itching to get a new pair of headphones since my grado 225's bit the dust a while back.
my absolute budget is $400 for a new pair.
i am wondering if all planar magnetic's sound as good as the OPPO.
right now now i going back and forth between Sennheiser 6xx or 560's both of which are in the $200 range
or if i am feeling "rich" the HIFIMAN Sundura's which seem to be going for $349 or so.

just was hoping for some feedback on those headphones or some other opinions.