I've has trolls and giants as PC's before, and I can say they have severe limitations.
While their innate base rate allows them to not need a horse and they are indeed walking pack animals, giant folk cannot enter most buildings, which relegates them to guarding the horses or, at best, sleeping in a barn/stables. This is if the townsfolk are not insane with fear, superstitions, etc. Food for such a PC is expensive (figure between 8 and 15 times normal). All gear cost a small fortune IF the crafter is willing to make it. They are very heavy, some small bridges wont support them nor will many wooden floors. It is near imposible for them to hide even with a +6 Ag mod and descent skill. All in all, they are a challenge to play and rather a pain.
Good for the gm, the innate distrust of most locals, particularly in smaller rural settings, is a door to adventures...none the PC's will care for. If lifestock come up missing or a child disapears or anyone gets murdered or falls sick, just guess who the locals blame? After all, everybody knows trolls are vicious and evil, blah blah blah.
A giant dwarf is rather ugly by human standards and might just be assumed to be a troll, or at least troll blood, and no good can come of that, should have been killed at birth it should have, would have been the kind and merciful thing, as any god fearing soul should know...
The Giantism talent is somewhat under powered to boot. I think there needs to be a talent for big (crit type I), bigger (crit type II), Large (LA crits) and massive (SL crits). Other talents could also explain critical reduction (resistant nervous system, Crit I, etc).
Some GM fiat will have to come into play with this talent. Just keep it fun.
