There’s a lot of difference in compost quality/composition out there. Where I”ve noticed it most is when I filter the stuff for exhibition purposes. Some bags you collect a huge amount of woody material that doesn’t go through the wider of my two gauzes, whereas others almost look like they have been filtered by the manufacturer. It will be interesting to see if the yields from the less woody composts are worse, the same or better than those I’ve used in the past. The quality of the potatoes grown has always been very high in the past, so it’s more a question whether high quality yields will increase or not.
I grow quite a lot of tomatoes, so I usually use a b25 litre ag of JI seed compost, two bags of Number One and three or four bags of Number Two just on those. So it’s a self-contained little production unit and it supports the local Horticultural Society buying it from them.
Everything else, I could happily shift to a Moorland Gold or other professional compost if it proves reliable for all things.