Pros
I worked at Substrakt for nearly 2 years and had a very positive experience.
For a West Midlands company of less than 40 employees, I was amazed at their reach with clients in North America, Europe and of course the UK.
They have a very good reputation in the arts and culture sector and appear to know everyone and are known by everyone in that industry.
Ash & Andy and the rest of the management team have created a great work culture, fun and supportive.
Kontras
Not much negative, it depends on your background and expectations.
It's mostly remote working, unless you live in the Birmingham area, but also they provide shared office access around the country for occasional group meetings.
It is also a smaller company, so may not have all the bells and whistles if you come from a larger company background.