I don't think you'll notice any particular trend in terms of one airline having more significant delays than the other. I've been tracking a certain US flight over the past few days. It has been cancelled twice, delayed 2 hours+ twice, and delayed about an hour on the other day; this is the main YYZ-PHL flight that passengers use to connect to European flights so these delays and cancellations are pretty significant.

I do, however, think you'll notice that front line staff (and therefore recovery from irregular operations) at US are often referred to as being the best in the business. There is a reason for that, as you've found out today.