Rewrite is often called Key's finest VN, and maybe it is, but it's also terribly boring and at best a mediocre VN, not a AAA effort.
All of the heroines are interesting, but their routes are mostly mediocre hack-jobs with the exception of Lucia's probably due to Ryushiki's greater talent. They all have giant plot holes , characterization problems, and like all mediocre VNs the heroine routes forget most other characters even exist.
The common route could easily be cut in half and nothing at all would be lost. The SoL comedy is bad outside of the Yoshino / chuuni segments and a few gag scenes.
The largest issue though is the laziness of the production. Several important characters don't have sprites. Very few CGs in comparison with the number of scenes -- and some of the few CGs we do get are of useless scenes like the ramen stand scene, Chihaya watching a card game, etc. Some high quality VNs can augment CGs with animated sprites and other effects to build a scene, but Rewrite does very little in the this department. In general scenes are very static, boring and lifeless. When the Harvest Festival comes, you would have absolutely no idea it was there if the fact wasn't bieng narrated to you. Now compare that with the festival in Summer Days -- visuals, audio, sound effects, etc, immerse you into those scenes.
So, in general, it seems Rewrite is just a mediocre VN at best, just longer than most in the genre.