I've used the FBO Cleo works for and it's good. I liked the service, nothing was a bother, they were prompt and nice facilities for both pax and crew.
If all FBOs were as pleasant to deal with this thread wouldn't exist.
There are some "FBOs" and I use that term very loosely that aren't worth the money.
No service, no assistance, don't even bother to come out to the aircraft, won't ring for a taxi etc and STILL charge like a wounded bull.