No Johns, but that was the first time I ever played 2.6b, and Calabrel was in fact probably better than me with Lucas at that point in time. When 2.6 came out I had to adjust a lot to not having a b-reversable magnet and force myself not to try using it, and I wasn't able to go back to using it very effectively right away. However I've gotten a lot better recently, and I just think most of my matches from before October are embarrassingly bad compared to my current skill level (which is not very high compared to Lucas's ridiculous skill cap).
Also, I can agree that dittos don't mean a ton, and certainly don't settle a debate over who is best with a certain character, but they are clearer than any other matchup since dittos eliminate questions about how good or bad a matchup is. It would be best if both players could play thousands of matches against all of the characters of every player in the world and see who does better overall, but since that is pretty unfeasible, we should look at the most useful data and use that to extrapolate. I'm pretty sure dittos provide better data than any other matchups since 1. we know 100% that neither character has an inherent advantage, whereas other matchups are almost certainly unbalanced in some way and 2. if it's a ditto between two players' mains, they both probably have a pretty good understanding of the character, which helps to minimize the risk that a player was just unlucky enough to play against a character they aren't experienced against. For example, this can happen in tournaments if you just happen to hit a character you're not experienced against, even though the player you're hitting could easily have been replaced in the initial seeding by another equally skilled player who uses a character you are experienced against. Note that I'm not trying to mitigate the role of matchup experience in evaluating how good a player is overall, but rather trying to minimize the impact of randomness, which just adds noise to the evaluation. It is entirely possible for a player with lots of experience against 28 of the characters to hit one of those 6 he isn't very experienced against early in a tournament, whereas another player with strong experience against only 24 of the characters (let's assume they're a subset of the other player's 28) could get lucky and not have to play any of his bad matchups. Obviously in the long run the player with broader matchup experience will do better if both are equally skilled in all other areas, but given the relative infrequency of tournaments (especially large ones), it can take a while for the results to align with what would be expected just given player skills and knowledge. The same thing applies to using friendlies (or seriouslies) as a basis for your judgment, since the matches that you play and that get recorded at smashfests are highly random and often just depend on who happens to be on the recording setup when you arrive.
Again, dittos definitely aren't everything, but they probably should be assigned more weight than other matchups. If we say that a random matchup has an average weighting of 1.0 in whatever formula we're using to evaluate how good someone is with a certain character, dittos might be weighted at something like 1.2-1.7 on average. The Lucas ditto probably requires a higher weighting just because the Lucas matchup in general will be of above average importance, since he is such a good character and will likely be a prominent threat once his metagame becomes more developed, but that is an entirely different subject that I won't go into here.