Touhou 7 isn't a perfect sequel. It's a worthy successor and introduces many great things to the table; more complicated danmaku, being able to visually see your hitbox and the enemy at the bottom of the screen, Youmu, and the introduction of gimmicks into the 1st Windows Era. However, I think it lacks on the character department compared to 6 and the music, a pretty iconic part of the series isn't as good this time. However, overall 7 probably is better than 6 just because of the QoL it introduces, and also Youmu.