I have not tried to avail paid service. Submission here is always beyond the limit.
I'm just using the free service.
Just as I've said, you need to check the time correctly and accelerate at exact xx:00.
Whenever I try this service always got "busy" notification.
I haven't encountered this busy notif but only the submission beyond the limit. I think that joniboini is right. With too many stuck transactions that we have in the network.
There will be a lot of people that are staying on it just to get acceleration and might even be created bots for it to auto-fill.