I tried signing up in two different states and was unable to in either for the first few days but now things seem to be working better. There is still a pause between screens but you seem to get where you're going.
The system has not booted me or crashed while I have been accessing it.
All really small complaints when I know there are no 15 page medical history questionnaires to be filled out only to be rejected for pre-existing conditions. Pre-existing no longer exists. That I am guaranteed to be accepted and that I have a variety of plans to choose from. That help is available if I can't figure it out or if I need help in choosing a plan.