I have been told by other people on this board that Youmu isn't very good due to charge time, scope and speed, but I find her very easy to use personally. I just meant that if I've 1cc'd the game on Normal mode as any character, rest assured I know how to charge, use my scope, play for score, exploit Lily's appearances, etc.
Youmu is one of the best characters in the game. At least for PvP!
Have you ever seen any high-end PvP matches or looked the East-Opera results? It's not as popular now because everyone is using either Reimu or Marisa but still very good.
East Opera the 1st (2006)
5 Reimu's and 3 Youmu's in top 8
East Opera the 2nd (2007)
6 Reimu's, 6 Youmu's, 1 Marisa, 1 Shikieiki, 1 Lyrica and 1 Yuka in Top 16
and some replays that are worth watching
East Opera the 1st 2006
A-block finals
Ric (Youmu) vs 司狼舞 (Komachi)
http://replays.gensokyou.org/download.php?id=9641B-block finals
ふぃあ (Medicine) vs rafin (Youmu)
http://replays.gensokyou.org/download.php?id=9642G-block match 7
VX (Shikieiki) vs
HS参謀 (Youmu)
http://replays.gensokyou.org/download.php?id=9643G-block finals
毛糸 (Shikieiki) vs
HS参謀 (Youmu)
http://replays.gensokyou.org/download.php?id=9644I-block match4
HS参謀 (Youmu) vs ぽぅぽぅ (Reimu)
Insane match. HS参謀 plays against the winner of the tournament. Too bad these guys had to play against each other so early. This should have been the final match.
http://replays.gensokyou.org/download.php?id=9645Grandfinals
rafin (Youmu) vs ぽぅぽぅ (Reimu)
http://replays.gensokyou.org/download.php?id=9646