What accounts for a good PhD experience? We know that there are multiple horror stories regarding people's PhD experience. 
I too had a minor setback : my advisor asked me to change advisors since my progress was not upto the mark.

What is it like to do good research? That is what could be the possible sufficient check marks I need to see in my program which would indicate if I should quit or strive ? I am asking this because not all challenges are positive and not all are negative.I was wondering that the more happier people might have not contributed enough on the e-community and it would be helpful to see the timeline of a successful and fulfilling PhD. ( we all know about the bigger Yes\No ( quals, defense etc) , I am more interested in the daily/weekly grind

Thanks
I don't think I've ever met a PhD student perfectly happy with their work, but there is a clear pattern among the few I knew who were doing quite well: a good work relationship with their PhD advisor. This means:


Shared interest in the topic and shared specific goals (it seems obvious but it's not always the case, far from it)
Good communication, and especially mutual understanding on how the collaboration works:


agreement on the balance autonomy/supervision, i.e. what the PhD student is supposed to do on their own vs. what they are supposed to ask their supervisor advice for.
clear communication policy: emails or meeting, meetings frequency, open door or scheduled appointments, etc.



It's a matter of finding the right way to work together between the student and the advisor. For example some advisors expect their PhD student to be quite autonomous, others prefer to be involved in every decision; both styles can work, as long as the student and the advisor are on the same page.

There is no general objective way to evaluate a PhD in progress, this is why good communication with the PhD advisor is essential since they are the only person who can give this kind of feedback. If the relationship works smoothly, the PhD student can be confident even when problems happen and doesn't waste too much time and mental energy questioning their own work.