Pros
Being around 3D Printers is probably the only positive. I got to meet a few decent people during my unpaid) employment.
Cons
The two directors are a complete nightmare and are very aggressive. During my unpaid employment I was shouted at publically for being 15 mins late due to transport issues Interns are treated like cattle and receive no real prospects towards paid employment. The company is basically using interns to populate their 'myminifactory' website with design files and they are treated very badly. There is no positive company culture and all of the unpaid employees are treated as expendable. The iMakr brand has an incredibly bad reputation in the 3D space and has been known to mislead potential employees and small businesses looking for funding. They openly advertise having funding available for 3D printing startups but what this actually means is you will join their company (unpaid) and develop your project under their name and allow them to take the credit. This is the worst company I have ever worked for and I welcome the day they close up shop.