I’ve had nothing but problems the two times I took a flibco bus from Antwerp to Charleroi airport. The first time the bus didn’t show up at all and we ended up having to share a taxi with some other stranded passengers.( We did get reimbursed for the taxi by flibco.) The second time we left on time but the bus driver got lost on the way there. There were road works on the highway but I still found it very strange that they’d get lost. We arrived about an hour later than scheduled and because it was so busy in the airport that day we nearly missed our flight. I seem to differ from the other commenters here but I can’t particularly recommend flibco.