Although this mic can be used for many applications, I am a vocalist and for my requirements I believe this is a great microphone for many reasons. Firstly, its frequency response is relatively flat so very little eq is required to make it sound great. There are no muddy bottoms or brittle tops to this mic, from bottom to top it is round, full and warm and enhances the natural quality of your voice. It is often used as a broadcast mic, so it has that ability to project the the bottom end of your voice but it doesn't muddy it, whether at the bottom or top of my range the mic provides great clarity and maintains the thickness throughout your range, whereas with slightly lower end 'industry standard' mics I can often feel my voice artificially sharpening or spiking in texture in certain places as I go up through my range. This mic makes transitions feel seemless as the texture of the mic is so consistent from top to bottom and for that reason, it always feels like its working with you.
Also. the proximity effect is incredible, it is easy to forget you are singing through a microphone as whether you back away or get anything other than right up to the grille of the mic, the volume and frequency changes remarkably little in comparison to the proximity effect on any other mic I have used. It resists pops and there are no issues with sibilence. Also, it is built solid, it is an extremely resilient mic and can take a forceful load (one of its other applications is as a highly regarded kick drum mic) so you can belt into this and feel 100% confident that it will replicate what you are doing. It also has great rejection, I use this whilst singing and playing the acoustic and whilst other mics such as condensers may pick more up in terms of detail or ribbons may provide even more warmth, they can be tricky for managing feedback, whereas this mic rejects noise brilliantly, for this reason, I think this is an outstanding microphone for live performance (although some may find it unwieldy and it is not designed to be held during performance)
In the same bracket the Shure sm7B is very well regarded and similar to this mic, but it is my personal opinion that this is simply because the 7b is cheaper and so is the lower hanging fruit between the two, I believe this to be a vastly superior mic, though of course these things are subjective and ultimately a matter of personal preference/requirements.
One thing I think is important to mention is that this mic (like many quality dynamics), is very low output, so for the sound to be fully realised it needs to be driven hard with gain. For this reason I thoroughly recommend purchasing either a Cloudlifter or Triton Fethead alongside this mic. These products provide a clean gain boost by utilising the phantom power in your preamps (it does not feed the signal to your mic so there is no danger to your mic). Since I have done this it has made the sound of the mic even bigger and even when played at the same volume, the difference in fullness (and the re20 is already full to begin with) between with or without a gain boost is quite significant.
In purchasing this microphone I compared scores and scores of mics (in studios and also by using an online comparison clipilator) and out of all the dynamics I have encountered thus far, it is easily my favourite and would require something pretty special to top it.
One last thing, I believe Thomann to be an outstanding retailer and their customer service second to none.