Are you asking how James *is*, or how Harry *wants him to be*?
We see very little of James. We see a desire-fueled image of him and Lily smiling benevolently down at Harry in the Mirror of Erised (which has nothing to do with reality — remember the Dark Lord would see himself as all-powerful and immortal), we see a reflection of him during Priori Incantatum, giving his son (who is the only one capable of bringing about an end to the war) dueling advice, we see a couple of memories of him, where arrogant, spoiled and cruel are the nicest things that could be said about him, and we see him once Harry puts on The Ressurrection Stone, where a shadow of him (that is not really him) effectively walks his son to his death.
Harry thinks the moon and stars of James. Harry thinks James was all that and a box of chocolate. One of my biggest pet peeves is everyone makes such a big deal about Harry being "The Boy Who Lived", but Harry didn't *do* anything (he wasn't capable anyway, being an INFANT). It was LILY that saved him, LILY that provided the protection, and honestly, Harry doesn't really seem to give much of a rat's tail for her.
Canonically, what we know about James is:
- He was intelligent (having made Head Boy);
- he was a pureblood;
- he was a spoiled, pampered child;
- he was prejudiced (he hated all Slytherins and all the Dark Arts on principle . . . he didn't have any apparent *reason*, as near as we can tell. Harry at least had *reason*);
- he was stubborn (he pursued Lily Evans unfailingly for seven years even after she more than made it plain — repeatedly — that she wanted absolutely nothing to do with him — in fact, I think if any other male insisted on going after a young female that way, they'd be brought up on sexual harassment charges);
- he was a good flyer and an extremely talented Quidditch player;
- he was nearly inhumanly talented at Transfiguration (becoming an Animagus is nearly impossible to start with, and nevermind as a child with no formal training; human transfiguration instruction doesn't start until sixth year and James had it down pat by fifth);
- he was quite innovative with regards to creating the Marauder's Map (which probably has heavy Charms emphasis);
- he was loyal to his immediate circle of friends;
- he was an absolute bloody MONSTER to those he didn't like;
- he was cruel and vicious to those weaker and less privileged than himself;
- and perhaps lastly, he had absolutely zero regard for the rules when the applied to himself (but everyone else should obey them, apparently), making him an incredible hypocrite (based upon his unreasonable dislike of Slytherins and Dark Arts, and his running about the castle at all hours, flagrantly disregarding the rules to run about the Forbidden Forest, and joining the Order in the first place).
I don't think Harry saw James as *needing* to be redeemed. He was his father, he was the best man that ever lived in Harry's eyes, and that was that. He didn't overlook James' behaviour "a bit"; apart from a few moments in Order of the Phoenix, he overlooked it entirely.
I don't like James much. Granted, I dislike Sirius Black equally if not more, but I will give Sirius this — he did *TRY* to be a good godfather to Harry in the face of some incredibly difficult odds. Note: I'm not saying that James wasn't or wouldn't have been a good father to Harry; I think Lucius was a good father to Draco. That doesn't mean any of them are good people. And I vehemently disagree that James was "a good person".