It appears Japanese players are in agreement.

[Sotek]

Actually Personal House and FC Housing will provide different benefits.

FC Hosuing gives benefits for DoH(such as High chance of crafting HQ items), exp, gil and anything more community based. Personal Housing provides more personal thing like stat boosts and stuff.

So... Free Company has no benefits, since HQ rates are at-or-near 100% anyway, and Personal Housing gives actual benefits, like increased Determination?