I never use any of the online chess training as my tactical game as always been half decent, I used to be able to play at a good level. 40 years ago I had a Fide over the board rating of 1870 and played the chess congress circuit for many years till I retired now only play friendly online. I think its quite easy to get ones chess.com rating up to 1500. obviously climbing it higher between 1500-2000 is much harder due to two factors the opponents ratings you will be playing and the points earned and lost are not too high so climbing a higher ladder online beyond 1500 becomes tougher to achieve.