Much depends on where you are located. If you are close to a Service Center, you will, most likely, get a better experience than if you are not. As for sourcing your own car and getting reimbursed, my experience was that it took them over six weeks from the time I sent them my receipts until the time I got my reimbursement. I had to "prompt" them quite a few times before someone actually told me that "the check was in the mail".
They gave me the number to the local Hertz manager, who I called, but never called me back. Granted that this was before the national Hertz deal was signed, but I really do not think it would have made a difference. They did not offer to provide any type of transportation to pick up said rental. I ended up getting something nicer from Turo and got pre-approval before doing so. It then took me six+ weeks to get reimbursement, long after I had already paid my credit card bill.