I thank you all for your thoughts and suggestions. I do want to say that only four of my 8 pots are pure compost and I also have 12 of my 20 plants in my in-ground garden. And I am STILL, as of the last batch of tomatoes, disappointed in the overall flavor. The compost I used in the pure compost pots was not purchased at the store-I got it from a farmer who uses a combination of manures mixed with wood chips and it is truly beautiful stuff. Sweet smelling and soft. In the four pots that have 1/2 compost and 1/2 top soil post I did purchase mushroom compost-it's not the same compost as the other pots. The pure compost plants and the ones in my garden are the best-looking. The leaves are darker green. But other than that, all 20 plants seem to be doing well and are producing lots of tomatoes. I'm hoping that this next batch, that are almost ripe, will be better tasting, since we've had less rain over the past week or so.
So many people counseled against using pure compost in pots, however, based on what I see, I'm not sure why. The least impressive of my plants are in the 1/2 mushroom compost 1/2 topsoil blend. There isn't a discernible difference between the ones in pure compost and the ones in the regular garden. I may try this again, next year, just to see if the results are any different.
As I drive around my neighborhood, I see several gardens with wilted, dead tomato plants-look like mine did, last year!!! Somehow, I seem to have avoided all those nasty Southern diseases. Wish I knew exactly why.
I think this is why tomato gardeners frequently have such varied and interesting solutions to producing great tomatoes! We do something, one year, have great tomatoes, and then we are convinced that whatever it is that we did is the magic bullet!! I'm already convinced that my lack of disease might be because I didn't do any foliar sprays and I didn't pinch back the suckers-but who knows, really, if that is it?