Dramatic license - some hate it, though it is necessary in retelling any life story. In the case of "Lucy", the main points of Lucille Ball's teenage years, early career and 20 year marriage to Desi Arnaz are all included, albeit in a truncated and reworked way.
The main emotional points of Lucy's life are made clear: Lucille's struggle to find her niche as an actress, finally blossoming into the brilliant comedienne who made the character Lucy Ricardo a legend; her turbulent, romantic and ultimately impossible marriage to Desi Arnaz; Lucy & Desi creating the first television empire and forever securing their place in history as TV's most memorable sitcom couple.
As Lucille Ball, Rachel York does a commendable job. Do not expect to see quite the same miraculous transformation like the one Judy Davis made when playing Judy Garland, but York makes Ball strong-willed yet likable, and is very funny in her own right. Even though her comedic-timing is different than Lucy's, she is still believable. The film never goes into much detail about her perfectionistic behaviour on the set, and her mistreatment of Vivian Vance during the early "I Love Lucy" years, but watching York portray Lucy rehearsing privately is a nice inclusion.
Daniel Pino is thinner and less charismatic than the real Desi was, but he does have his own charm and does a mostly decent job with Desi's accent, especially in the opening scene. Madeline Zima was decent, if not overly memorable, as the teen-aged Lucy.
Vivian Vance and William Frawley were not featured much, thankfully, since Rebecca Hobbs and Russell Newman were not very convincing in the roles. Not that they aren't good actors in their own right, they just were not all that suited to the people they were playing. Most of the actors were from Austrailia and New Zeland, and the repressed accents are detectable at times.
Although the main structure of the film sticks to historical fact, there are many deviations, some for seemingly inexplicable reasons. Jess Oppenheimer, the head writer of Lucy's radio show "My Favourite Husband" which began in 1948, is depicted in this film as arriving on the scene to help with "I Love Lucy" in 1951, completely disregarding the fact that he was the main creator! This movie also depicts Marc Daniels as being the main "I Love Lucy" director for its entire run, completely ignoring the fact that he was replaced by William Asher after the first season! Also, though I figure this was due to budgetary constraints, the Ricardo's are shown to live in the same apartment for their entire stay in New York, when in reality they changed apartments in 1953. The kitchen set is slightly larger and off-scale from the original as well. The Connecticut home looks pretty close to the original, except the right and left sides of the house have been condensed and restructured.
There's also Desi talking about buying RKO in 1953, during Lucy's red-scare incident, even though RKO did not hit the market until 1957. These changes well could have been for dramatic license, and the film does work at conveying the main facts, but would it have hurt them to show a bit more respect to Oppenheimer and Asher, two vital figures in "I Love Lucy" history? The biggest gaff comes in the "I Love Lucy" recreation scenes, at least a few of them. It's always risky recreating something that is captured on film and has been seen by billions of people, but even more so when OBVIOUS CHANGES are made. The scene with the giant bread loaf was truncated, and anyone at all familiar with that episode would have noticed the differences right away! The "We're Having A Baby" number was shortened as well, but other than that it was practically dead on. By far the best was the "grape-stomping" scene, with Rachel York really nailing Lucy's mannerisms. The producers made the wise decision not to attempt directly recreating the "Vitametavegamin" and candy factory bits, instead showing the actors rehearse them. These scenes proved effective because of that approach.
The film's main fault is that it makes the assumption the viewers already know a great deal about Lucy's life, since much is skimmed over or omitted at all. Overall, though, it gives a decent portrait of Lucy & Desi's marriage, and the factual errors can be overlooked when the character development works effectively.

I haven't read a biography of Lincoln, so maybe this was an accurate portrayal......
And maybe it's because I'm used to the equally alienating and unrealistic worshiping portrayals that unnaturally deify Lincoln as brilliant, honorable, and the savior of our country......
But why would they make a movie representing Lincoln as a buffoon? While Henry Fonda made an excellent Lincoln, his portrayal of him as an "aw shucks, I'm just a simple guy" seemed a little insulting.
[Granted, that was Bushie Jr.'s whole campaign, to make us think he was "just a regular guy" so we wouldn't care that he's a rich & privileged moron -- but that's a whole other story.]
Not only did the film show Lincoln as sort of a simple (almost simple-minded) kind of guy , the film states that Lincoln just sort of got into law by accident, and that he wasn't even that interested in the law - only with the falsely simplistic idea of the law being about rights & wrongs. In the film he's not a very good defense attorney (he lounges around with his feet on the table and makes fun of the witnesses), and the outcome is mostly determined by chance/luck.
Furthermore, partly because this was financed by Republicans (in reaction to some play sponsored by Democrats that had come out) and partly because it was just the sentiment of the times, the film is unfortunately religious, racist and conservative.
Don't waste your time on this film!