Ok.All custom firmwares are good for gaming purposes.There is however,one reason why most people (usually devs) prefer to stay on 3.71m33 instead of upgrading to 4.01m33.

They tend to use plugins.Plugins come in the form on prx's and it allows a user to run their desired code either during a game,while scrolling in the XMB or when running a ps1 game on their psp.Other than this,there is no other reason to stay on 3.71m33.It's best to upgrade to 4.01m33.

Once you've upgraded to 4.01m33,and if you do not like it for some reason,you can always reflash it to 3.71m33 using Hellcat's Recovery Tool.My guide : Recovery Flasher

Now,if you wish to upgrade to 4.01m33,do the following.

1)Go to recovery mode and set your kernel to 3.71 (Recovery : Hold the off switch for about 3-4 seconds,then HOLD R and boot your psp up.You should be in recovery                                                                                      mode.Now go to configuration,and hit X at the third option (Game Folder Hombrew) until it says "371".

2)Then download 4.01m33 files

3)Download this too 4.01 official eboot

4)Now open the 4.01m33 installer (step 2),and you should see several files and folders including the UPDATE folder.

5)Copy the UPDATE folder and paste it in PSP/GAME.

6)Now,time for the 4.01eboot

7)Copy the 401.PBP and paste it in the UPDATE folder as well.

8)It should be like this ms0:/PSP/GAME/UPDATE/eboot.pbp && 401.PBP

9)Execute the installer from the game tab.

10)After the installation finishes,REMEMBER TO CLICK X OR YOU'LL BRICK.

11)Done! Enjoy!