I was also bitten by H. gigas. Specimen was approx 1.5", was an escapee that "found" me while I was on the couch. I am allergic to insect bites and stings and found it to be relatively nothing exciting. I thought I'd have more reaction than I did. The bite was on my right forearm and I didn't even know I was bitten until I felt the area get hot. I looked down to see the tell-tale puncture mark(x2) and must say I didn't see the spider at this point so I can't be 100% positive this is what bit, although I'm 95% sure.
The area swelled and got very hot for about two hours, I'd say the raised up area was the circumference of a tennis ball. After about two hours I experienced very mild itching for approximately 1/2 hour. I was left with a bit of a scar in the area, nothing to write home about.
All in all it wasn't even remotely as bad as I thought a T bite would be for me, considering my allergies to bees, wasps and ants. Could have been a dry bite. Could have been a love nip. Who's to say?