I have not seen or heard the CM5. I have seen and modded several CM6 mics and have seen the build quality. The components that are used are better than the Apex counterpart, and the transformer coupling capacitor is a stacked film capacitor. I am not sure of the origin of this capacitor. I use some Seimens stacked film capacitors in my MK012 mod. The Seimens caps do sound quite good.
The circuits that I use in the Dutch microphones are plate follower circuits. These circuits let you hear the sound of the tube and transformer better than the cathode follower circuit that is in the other renditions (Apex, Advanced Audio, Avantone, Carvin, Nady, ETC).
The components that I use in my microphones are some of the best available. All of the electrolytic capacitors are high grade NIchicon,Panasonic, Elna,and Rubycon. The Film capacitors I use are high quality Wima, Phillips mustard caps, Paper in oil capacitors, Seimans, Elco and many other brands. I use the polystyrene and Silver Mica in critical locations.
I use two transformers in the Dutch, Jensen and Tab Funkenwerk. The Jensen is clean and transparent with lots of headroom. The Tab is a recreation of the Hiller transformer and has nice warm accurate sound. The Tab is the most popular choice for that vintage sound.
The stock capsule that I use are similar to the CM5 and the CM12 mics. The upgrades that I offer are the ADK CK12 and the Tim Campbell CT12. I am currently auditioning a new capsule that I may be offering as the stock capsule.
I also rebuild the power supplies so that they provide the proper voltages and the very best filtering for the tube mic.
All of the mics and power supplies are rewired with Teflon Belden or Alpha Mil Spec Silver plated copper stranded wire.
As you can see this is a custom microphone. Lots of options. It takes time to change the circuit, capacitors, wires, capsule, and transformer.