If this season wasn't filled with pointless (and often boring) filler episodes, it would overshadow the first season completely. 12 out of the 25 episodes in this season are fillers, and most of them are ones I'll never watch again. However, on the positive side, the animators finally fixed that nasty "still frame" habit with the fight scenes.
The animation isn't perfect, and there are still some "no contact" scenes which plagued the first 50 episodes, but the fights are much more immersive. Unfortunately, it dropped in the "sound" rating, because not only do I find the second intro song annoying as heck to listen to, but some of the BGM music isn't as strong or appropriate as the first season.
I won't be dedicating a section to the characters, since they're the same from the first season (with the exception of a new antagonist, "Kami-sama", but saying anything about him would be giving away a lot about the plot).
Story
Still about a hodgepodge group heading to India to stop the Minus Wave, and the situations they encounter along the way.
The major story point starts in episode 17, and runs to the end (episode 25). This is known as the "Kami-sama" arc, and the anime covers volumes 7-9 of the manga. I did have to dock points for some pointless fillers, but the Kami-sama arc is strong (granted, if the Kami-sama arc wasn't in the Reload anime, the story and overall rating would be much lower).
The rest of the episodes range from amusing to dull. There are a couple episodes (14-15) which are almost a repeat of the desert episodes we saw in the first series (Sanzo is poisoned, group is running out of time, Kougaiji offers a flying dragon in exchange for the scripture or a fight), only Goku doesn't go berserk/Seitan Taisei in it. It's probably the worst anime original set of episodes in the entire Reload series.
What really makes this season worth watching are the laughs in the earlier episodes, some of the surprisingly interesting fillers, and especially the Kami-sama arc.
In the market, Gojyo meets up with/saves a young youkai, and winds up chatting with him. The boy misunderstands Gojyo's talk about his companions, and gets the impression that they're "bad guys" to be eliminated.
Things spiral down from that, and the new antagonist makes his appearance not to long after the misunderstanding is cleared up; the childish sociopath with no name, who is merely called "Kami-sama".
The "Kami-sama" arc is quite possibly a 9/10, but the rest of the story is mere fillers.
Overall
The filler episodes are amusing to watch, but the real gem is the Kami-sama arc. Unlike disappointed fans everywhere when we found out that volume 7 of Saiyuki Reload wasn't animated in Gunlock, the Kami-sama arc did finally make it into the anime, and didn't deviate from the manga.
Because the fight scenes (even in the filler episodes) are much better in terms of animation and immersion than they were in the first season, my rating of this season goes up.
To be honest, the episodes I always wind up rewatching are the Kami-sama ones (17-25), but it actually is the only Saiyuki season which has the least amount of filler/anime exclusive episodes (totalling 12) or episodes which deviate from the manga version.
Again, I did have to dock points off the story for some of the filler episodes; most of them, I wouldn't mind watching again, but there are a couple (like episodes 14-15) which I'll never look at a second time. The recycled story in those two episodes was what really made me dock points off of the overall story, even if this season DID cover the Kami-sama arc.
As much as I would have wanted to see the Kami-sama arc in the first season (as it occurred before any of the events in Reload in the manga), I'm glad that it was animated in the Reload anime and not the first one (as there's more immersion in Reload).
All in all, Reload (particularly the cover of the Kami-sama arc) is one of the strongest (well rounded) seasons in the whole of the Saiyuki anime.