well ninja look like mat rempit, my brother have it, he say maintenance is expense because it 2 stroke engine. 2 stroke use heavyly and need change moto oil every month depend on your uses.

before this he uses r25, and lc135 1st endition and motor cross. he fav is lc3 because cheap maintenance.

speed R25 almost same like ninja but ninja more 10kmh only. but ninja not very stable because ninja very light compare with r25. for short people, ninja is good for them cause you leg can get down.