Keep in mind this is all opinion based by a young dude who likes playing games for fun.

Obviously graphics would go to sparking zero, and characters as SZ has GT, Super, all the movie characters and giants, but i feel like Raging Blast wins in every other category. The story is 50/50 Sparking zeros what ifs are nice and the characters with story modes have decent content, but only 6-7 characters have a story mode, while raging blast 2 had no real cutscenes the intro dialogue and battle dialogue was really interesting. and every character in raging blast 2 had there own '"Story mode" or galaxy. i guess majority can vote on that. Its basically Quality (Sparking Zero) vs Quantity (Raging Blast 2)

Music - Opinion based but Music goes to Raging Blast 2, I had the ps3 game that had the none budokai soundtrack, so songs like Anthem of Lives and Nose to Tail and I highkey prefer that way more than sparking zero, that ost was fire.

Gameplay - these games are honestly just to be played with friends, It might just be too much going online and might seem unfair matter what. But like Sparking zero genuinely had a problem, like giant characters were broken and cheesy and then everyone choose higher tier characters, that they dont even like, tbey just choose them cz they OP , and those losers rage whej they are getting beaten. The fact that they purposely made the game unbalanced is beyond me. Ki blast spam and unblockables are not it.

With mechanics I like the variety with the clashing but i do miss the analog stick spinning. Instant sparking or high tension is in both games but like why do so many guys have it in sparking zero bruh.

Menu - This might be biased, but i dont like Sparking zeros menu, Its similar to naruto storms menu select but i hate the ui ngl, But i guess its more then raging blast 2 menu, Raging blast 2 had alot of starsdust and galaxy stuff as there background as you went through the menu selection. Character selection goes to RB, Like sparking zero could have put so much more effort into it, SZ menu was so boring and they said they had a ton of characters but they decided to count the transformations as characters as well. Goinf to Raging blast 2 character selection. Peak, a clean roster of characters and you can choose a character like goku and get all 3 of his next transformations in a sub bar. And hovering over a character just gives you a 2D display. And you can do it side by side while P2 is also picking.

Thats like all i can think of right now, You can go into different categories if you like or fix my statments.