i used to be a customer of Group Bitcoin. I collocated a SP10 with them but 2 months ago they were supposedly kicked out of there warehouse as they were generating too much noise and heat. all though these guys had good ideas and were very enthusiastic, they can be a pain to get hold of.
last i herd they were looking for somewhere else to locate there mine. i did ask for them to contact me when they found a location but have not herd anything.
P.S. Has anybody actually visited their Mine said to be somewhere in Essex ?
i did visit the mine, and was quite impressive. there mine was well built and did have an office and storage. as well as the man trap. although i believe i didn't see the whole structure as they claimed to have more hashes than i saw miners but this could have been the collocated miners i saw. the photo on there website now is of a new mine so hopefully they have survived.
Unfortunately they did ask me not to share the location for security of the miners and collocated miners.