I went ahead and did Yuzuriha's path, since it and Sera's branch off from one another.  Despite this fact, Yuzuriha's path is quite distinct from Sera's, so you don't need to worry about all of the text repeating or anything like that.  Yuzuriha's path does have one thing in common with Sera's though... and that is that the relation formation stage is pretty long.  In both cases, there is a lot of back and forth, chasing and being chased, and if you have trouble with that, this path might be a bit frustrating for you. 

Once you get past the formative stages, you get a cute couple... who are really slow about moving forward (this was the case with Sera as well), probably because Kiyosumi is pretty bad at reading people sometimes and tends to hold back rather than stepping forward most of the time, though he can be assertive when he needs to be.  Again, for people who don't like this kind of relationship development, this path might be troublesome for you.  I honestly got the urge to skip through this path repeatedly along the way, just so they would get to the drama... which was sort of anticlimactic.  I guess it is because the actual events in the common route have so much impact, but the heroine paths in general feel like a winding down into 'normal' life afterward... and this is supported by the fact that so far, the ending epilogues have gone forward at least into married life after the main path's end.  Of course, there are a lot of laughs along the way (love-comedy antics, mostly), so it isn't like the ride is boring, but the common route and the endings are the flower of this VN, more than the actual paths themselves. 

PS: The main reason it took me all day to get this far?  Drowsiness from the pain drugs... I keep falling asleep.