Honestly, all i can tell you is my own experience.Last winter, i had to use my generator 5000 W. I powered up my 56 inch flat screen, with no problem,with a really good surge protector.I was very careful not to put too heavy a load on the generator, while using the TV, so the voltage spikes were at a minimum.
Don't know if its adviseable or not to do it this way , but i had no problems with the TV afterwards