I have a Arc100LTD, 3U5, SP code. And I feel it is very heavy, even heavier than Arc10. It has a balance point around 293mm. And I use an electronic weigher to weigh the racket (without string, including PVC heat shrinking film). It is 92g. Even without the shrinking film, the weight goes beyond 3U range (85-90g). What about your Arc100, I don't know if my arc100 is specially heavy or all of these type are heavier that other 3U rackets.
my arc100 is similar in swing weight as my arc10, both 3U. i don't find it especially heavy. US code.