The seven games that started two weeks ago have all advanced to around moves 8-12. All of them are still in theory, meaning that I can find games on Chesslab.com with the same position I'm playing. Of the seven games, three are still in basic theory, where hundreds of games have already been played to the position in my game. In one of those three games, my opponent is taking a 'long think' to decide between two theoretical moves of equal importance that branch into completely different paths.
Of the other four games, three are in positions where I find 10-20 previously played games. In all three of those games, one variation has been played more than any other, and the effort required on my part is to understand why that variation is so popular and where it will eventually lead. Previous experience tells me that all of those games will eventually reach a position where several different moves have been tried, each move having a handful (less than five) of representative games. That's the point where I have to start thinking for myself.
The last of the seven games has already reached the 'handful' stage. That, of course, is where the chess starts to become interesting because I'm really on my own.
In contrast to those seven SP518 games, I just started two chess960 correspondence games, one with White and one with Black. Both games are on the first move and I'm already on my own. I know from experience that the CCRL database (see the link in the right sidebar) is unreliable for opening ideas, since engines just don't understand the opening. I also know that I won't find more than a few dozen games elsewhere using the same start position, many of those between players who have a different idea about opening objectives than I have.
I know that preparing for correspondence chess is not the same as preparing for crossboard chess. In fact, preparing openings for crossboard chess is even more time consuming and the work is never finished. In a world where time is a limited quantity for all of us, that pretty much sums up why I prefer playing chess960.