Vantaggi
No plus point. They literally did nothing for me, other than get a percentage cut for me from the client.
Svantaggi
They do not care about their contractors and never pay on time.
Regarding payment, they are sometimes late a few days, sometimes, few weeks (!). This has happened almost every month, over the course of two years.
When I tried, multiple times, to discuss this with them, I hit a wall, and initially, I got all kind of bad excuses back. Either the employee responsible with payments was on holiday, or he was on training, or sick.
After a few attempts of discussion I got completely blocked -- not even a reply to my messages.
There were many contractors from Qualogy working with my current client and most of them left (same will I), and most were unhappy.
Do NOT work for this company, or prepare to be disappointed.