I've done Peak Rail and Ecclesbourne, taken bikes on both.
I found Ecclesbourne to be more interesting (and more useful - covering a longer distance), partly because you can see out of the cab from the DMU.
The Ecclesbourne Railway tries its best to connect with EMT and it worked well for us.
Peak Rail did
not connect, in fact the train was timetabled to arrive
at the same time as the EMT service departed from Matlock. With it being a difficult connection, it was not surprising that we missed it (we were late anyway), it's not an easy change, you have to effectively go out of the station and back in. Faced with a
2-hour wait, we cycled to Alfreton instead. So it may as well have not connected at all!
The staff/volunteers at both were friendly enough and were helpful with regards our bikes.
We also got a cheaper fare on Peak Rail than we expected which was a bonus. I can't remember the cost of either, both were singles, but I remember thinking they were very reasonable at the time.
It's no more than a three minute walk across the foot bridge and down the foot path towards Sainsbury.
True, but in our case it was 0 minutes or 120 minutes. So there was no option but to allow "plenty" of time

Except we went to Alfreton instead as a wait of that length is bonkers. The train was empty, and I did wonder if the 2 hour wait just might have put people off. Possibly...