I think Pete has admirable qualities. Sure he bitches and moans every time he stubs his toe but that doesn't stop him from pulling the cart all the same. The dude carried SCDP on his back during some awful lean times and wasn't ever really acknowledged for it. Sure you could say he was just doing his job, what he's paid to do, et cetera, but he went above and beyond the call of duty when it came time to pull through for the firm.
Then you delve into his personal life, his politics, and the demeanor cracks and you see a person who actually cares about things. I don't mean things like a nice house, but things like social justice. He's like the Anti-Don. He doesn't mope and get drunk to forget his troubles, he bitches and moans while solving his problems. I think his actions get lost in the cacophony of his epic bitch fits. If we're to judge a man by his actions, then Pete Campbell is a pretty solid guy, all things considered. I wouldn't be surprised of Two Cups recognized that.
Now I'm sure someone wants to bring up his cheating on Trudy, and here is where the dark side of Pete comes into play. The show has never hid the fact that he's terribly insecure about his personality, his looks, his position. He's been growing distant from everybody in his life because he probably feels like they take him for granted. Or probably worse, they see him for who he is - an insecure man who is begging for approval from anybody. It'd make sense, I think, to seek validation outside of his circle of friends and family in order to feel like he's worth something. I think that's what the romance fantasy with the girl at the driving school was about. He saw an opportunity to make a positive impression and leave someone with the idea that Pete Campbell is a man's man. He's a reliable man. He's essentially a Don Draper, or at least, the idea of Don Draper as Dick Whitman presents him to the world. When the girl subtly rejects him at the driving school, that fantasy of being a Don Draper type is ultimately shattered. It leaves him bitter and looking to seek his validation elsewhere.
That's what I think of Pete Campbell, anyhow. He's got his issues no different than anyone else, but when pushes comes to shove he's someone you can depend on.
EDIT to add:
I think my favourite scene from this week's episode was Pete and Peggy drunk at dinner. Pete let his guard down and he was a very sociable, funny, and charming guy. I think the worst thing about Pete is that he's so often tightly wound to hide his insecurity that he can't see that the "real Pete Campbell" is actually a cool dude to be around.