Do not go by the testimonials on the website of the ICT Company. That can be altered. Try to contact the client and speak with the IT team directly. They will give you the real feedback about their ICT Partner. Check for the ISO and other quality standards which the ICT provider.
Follows and the certifications they have achieved. If the quality standards are poor, then your network will face a huge threat. There might be the threat of invasions, virus attacks and the data stored in your servers might be compromised.