In October 2008, THQ and Volition released Saints Row 2 for Xbox 360 and PlayStation 3 to positive reviews and commercial success, with it being widely regarded as the best game in the entire Saints Row series. Three months later, the original Windows version was developed by CD Projekt Localisation Centre (currently known as GOG Poland Sp. z o.o.). It was released to the public with terrible results.
This game had low quality soundbanks (22,5 khz) compared to the Xbox 360 version, where it ran at 32 - 48 khz stereo.
The game sometimes flicker and screen-tear when you connected your PC to a TV through an HDMI cable.
The GOG version of the game was locked to the wrong frame rate, and with the Gentlemen of the Row mod, it got worse.
Datamining by modders revealed portions of the console-only DLC existed in-game, which provides the post-story bridge to Saints Row: The Third, but there was not enough present to reconstruct it for the PC and modders had been forbidden by the publishers to attempt to port the console assets, as the provisions of the port explicitly forbid doing so.
Fortunately, there's modifications such as Gentlemen of the Row, High Quality Radio (ported from the Xbox 360 version), and Saints Row 2 Powertools, which fixed most of the problems that the port suffers from. They may not be perfect, but at least they make this disaster of a port more playable and enjoyable.
There's also a ton of graphical improvement mods (like FusionH2o's Saints Row 1 Texture Pack, which replaces many of the game's textures with those from Saints Row, giving Stilwater a more vibrant and livelier feel).
On October 2019, Volition announced that they found the source code for this port and will be releasing a patch for it in the near future. Changes included replacing GameSpy with Steam (allowing for Workshop mods), various bug fixes, and also including the DLC content for free.