I bought a small batch and tried them out in my own studio down in Devon. The ‘GP’ mic was very good, but very shortly after trying it, there were some business changes at SE and so I did not go ahead with it as a product line. It’s a perfectly good large diameter capacitor mic that I would use anywhere.
I do have one of those here and it can suffer from humidity problems causing high background noise. The fix is to keep it is a warm cupboard for a week or so to dry it out well. 