My experience with the feltpads from 8trackavenue are good. I have been able to improve the working of many tapes that otherwise would not have worked correctly. In fact, I posses somewhere between 100-200 tapes and I have only thrown away a couple.
But, a good recording deck is essential. A have a DCC600 that does the job for me. By trail and error I found that thát deck (and not other DCC600’s that I have) is the best deck to record on, meaning that I have the fewest dropouts in the recordings and the recorded tapes are the most compatible amongst all my machines. Other decks may record and play well, on that same deck, but tapes appear to be incompatible with other decks: they produce no sound or a lot of dropouts etc.
This is my experience for my situation and I believe that for instance Ralf has other experience.
It’s a learn-as-you-go hobby.
Also, the new felt pad can solve a lot of mechanical issues with the tape, but not if tape has been physically damaged. That can happen for instance when a tape has been played on a head that had dirt on it. Remember that the tape is very, very thin and fragile. Dragging the tape along a head which has a dirt patch/lump stuck to it (however small) can create longitudinal deformities that can render some DCC tracks unusable across the entire length of the tape.
Also I have had some occurrences of tape salad inside the shell/tape mechanism, where the tape is crumbled at some point. The tape will be wrinkled there. At such spots, the DCC format will never be able to record all tracks without error. So dropouts will happen there. After that spot, the tape is usually fine again. I have this on my much beloved Love Over Gold DCC that has dropouts in some parts due to damaged tape.
Changing the pads takes only a few minutes, most of the time is waiting for the alcohol used to solve the glue has vaporized so you can apply a new pad. Nothing to it.