I unfortunately had to use their services seven years ago when my old boy was PTS - it was all arranged by the vets so I didn't have to contact them directly.
When they came, there was a woman doing stuff; and she was absolutely superb at a difficult and awful time. Advised me to stay out the way and let her do what she needed to get on with, and basically got on and did it.
In due course I got the ashes back as requested.
Apparently the woman (can't remember her name) is also a Licensed Knackerperson and can despatch animals humanely if needed/requested.
I used them last November as my friend recommended them. I personally didn't liaise with them as was in bits over having my horse PTS, so my vets arranged everything.
Unfortunately, they turned up an hour or so late (vet put my lad to sleep), as they couldn't find us (they were very apologetic). Then I never got my boys ashes back, which caused great upset. I had specifically requested the ashes, and spoke to the lady at Cremtor and my head vet, each blamed each other.
I would use them again but I'd make the arrangements myself.
If you are wanting to use them to have a horse shot rather than PTS by vet I can not recommend them highly enough! Sally is extremely professional and sensitive to owners wishes. I chose to use her when it was time for my mare to go and I can honestly say it was the best way for my mare. Feel free to PM me if you want to know anything else.
I fully agree with Poo Picker re service.
Nobody wants to use them but it is a fact of life and having a woman put down my horse was strange but he did not like men Sally was gentle very professional and I felt I had given my dear boy a dignified end.