On a rather unusual shop with high fee and very high reimbursement, I e-mailed the MSC my purchase receipt as I was walking to my car and was paid my fee and reimbursed minutes later. I hadn't even left the parking lot. I submitted the report itself two days later. But, again a rather unusual shop.
That said, I 'd prefer IPSOS to pay only one or twice per month. I find every few days administratively burdensome.