Meh 78mb tooo slow, 120mb virgin for me (soon to be 152mb).. infinity is fine tho, i know a few people on it.
That said i would recommend you forget their router/modem (use it only as a modem) or just ask for a separate FTTC modem and then a router using proper QOS (eg something running dd-wrt or openwrt), that way you can ensure that JO gets high priority over other traffic.