No, not really, they got loads of disadvantages. They need much more water. They might not get suitable equipment in their size and if so they have to pay much more for it (So the 2d4 for unarmed attack might be their unvoluntarily choice). Maybe they just fit in some narrow passages. Maybe this causes them to be the virtual meat shield for a party, preventing anyone else to be hit?This is great- just OOC, are you concerned that the Half Giants are, well, too much?
Enemy controller casters (do not forget psionics ) would go for the big guy first. and so on.
Otoh i did not go for attributes bigger than 20 for them e.g. str 22 or 24 but they have to get compensation for that. The 1d4 extra damage in melee just does the job fine. Maybe they should get reach? Yea i think they should get reach eventually.