Review:

The anime is slightly different from the manga version. While most of the story and characters (e.g Ryoma Echizen, Takeshi Momoshiro, Shusuke Fuji) are the same, there are small story-changes in the animated version because Konomi thought it would be too boring to watch what fans have already read.

Table tennis scenes and billiard scenes exist in the anime, but not in the manga.
The tournament in which Seigaku faces Midoriyama in the manga, they switch the tournament draw and put Jyousei Shounan to face Seigaku.
Some events take place at different times. For example, Kirihara visits Seigaku in the manga prior to the District Regionals, but he doesn't meet them in the anime until after the Tokyo Prefecturals. Inoue and Shiba also visit Nanjirou much earlier in the anime then they do in the manga, and are introduced earlier (in the manga they don't show up until Ryoma's match against Inui)
Also, the anime starts shifting from the manga starting from the Rokakku arc. In the manga storyline, it is not Ryoma who faces Kentaro Aoi, but rather Kaoru Kaidoh.
In the anime, Ryoma faces off against Sanada before the Rikkaidai match and gets crushed. In the manga, he plays against Kirihara before the match, activates the State of Self Actualization, and wins.
The manga shows growth in tennis skill through modes of self-actualization. The anime does also, but only until the OVA arc.
The episodes in the anime dealing with Kevin Smith and the U.S. West Coast Team do not take place within the manga.
While the manga makes an attempt to try and explain how some of the seemingly impossible moves are performed, such as the Tezuka Zone and Kikumaru's Seal Steps, the anime does less and sometimes even exaggerate them to a point where it becomes almost magical. This is possibly also due to the fact that the anime uses animation and naturally some effects are enhanced. But at times it seems that the anime is deliberately exaggerating the effects in order to parody itself. In the animated movie, Tezuka's skill and power has been compared to that of the meteorite which led to the extinction of dinosaurs in a lengthy clip; even the author found it so exaggerated that it was funny. Another instance is Ryoma's anime-only Cyclone Smash which, unlike many powerful smashes in the series which blows away the opponents racket, blows away Sanada completely.
When Tezuka is injured, in the manga he goes to Kyushu for his shoulder. However, in the anime, Tezuka goes to Germany instead. In the OVA, however, Tezuka is also said to have gone to Kyushu to recover his confidence in his shoulder.
The anime (especially the anime-only stories and chibi episodes) sometimes parodies and even makes amusement out the story itself, for example, Inui Juice, Tezuka Zone, and Fuji in his open-eye mode. Overall, the manga is more serious and does not tend to make jokes or more amusing matters.