As long as there is no repeats of Hillsborough and Ellis park- at an event there should never be complaints.
I always thought ultras were basically the same thing as firms. Plenty of those in England, Naughty Forty is Stoke's big one.
Our fans (Crystal Palace) are about the closest you'll get to Ultras in this country (for atmosphere, colour, passion at least).
I have been to many Premier League games through my lifetime, mostly at Villa Park but at some other grounds too. I am glad we generally don't have a bunch of idiots throwing fireworks and making racist or other offensive chants but that doesnt mean we don't have great atmospheres, some matches better than others for sure but I've been to some truly memorable games with unbelievable atmospheres.