ditto. bland.

"(And I couldn't have bought Holden as a struggling young writer with Patricia Neal as a sugar-mama.)"
Good one!

At 43, I think Holden would have been too old for the role. Audrey looked younger than her years in this, IMO, and I think Holden always looked older - more mature? - than his. Given the (overall) story, and to contrast Doc, I think it was important that Paul and Holly both looked to be young - late 20s - and of the same age, and I think in this regard Peppard was a good choice. (And I couldn't have bought Holden as a struggling young writer with Patricia Neal as a sugar-mama.)

no kidding, since Holden and Hepburn already had had a sexual affair during Sabrina

I've always said I would have loved William Holden in the role, but I imagine Mel would have objected to that even more than Tony Curtis!

I saw him as dull at first, but as the film progressed that quickly wore off. He seemed colorful and alive enough during the party scene and of course towards the end when he falls in love with Holly. I like that he didn't overact, which I do feel Audrey did at times, but showed enough emotion when needed. Plus, he was kind of nice to look at too.

True. His breakout role was in Barefoot in the Park (1963) so it was a few years after Breakfast at Tiffany's. But he would have made a good Paul Varjak all the same.

Robert Redford was a nobody at this time

If true, fortunately that doesn't come across onscreen. I honestly can't see Tony Curtis, Steve McQueen, or Robert Redford as a fit for the role of Paul opposite Hepburn's Golightly. Peppard will always be the one and only "Fred Baby." I don't see him as dull, just very mild and laid back. He loses some of that though after he falls in love with Holly.

At least (though not a great actor) Redford is a nice guy. By the end of the movie even Audrey Hepburn (who got along with everyone) couldn't stand Peppard.

I was never a George Peppard fan until I saw Breakfast at Tiffany's. He had the right amount of humor and compassion when scenes called for it
and
he was attentive to Cat.
The director wanted Paul Varjak to seem like more of a pushover, such as when dealing with "2-E," but I'm glad Peppard insisted on playing the role with more of a backbone.

Even Redford would have been better.

yeah, he kinda sleep walks thru the movie, but at least he wasn't over acting.

No. Among other names, Tony Curtis and Steve McQueen were being considered for the role. Audrey's husband didn't want her working with Curtis for some reason, and McQueen was unavailable. Blake Edwards reluctantly gave Peppard the role because the other producers liked him.