I liked Lou, but I was a Curly fan at heart. A lot of people don't realize how good some of those comedians were, but in the Who's on First skit, for example, their timing is perfect. I saw a movie about their lives, with Harvey Korman and Buddy Hackett playing the leads. Those two were excellent comedians, but when they did the Who's on First skit, the timing was a little off. When Abott and Costello do it, there's just enough of a pause that Lou appears to be thinking about it, and the audience has enough time to pick up on the double meaning. Lou jumps in with his comment quickly enough that it doesn't drag, though.
There was a lot of comedians of that era that were terrific. I think the thing that separates them from later comedians are the years that most of them put in on the radio. On radio, the timing was everything. Also, I think the later comedians rely too much on blatant off color and filthy language. The only ones then that did were on the bar and road house circuit and they were few.