I took my favorite UMD Demo disc (UCJB-98302) and made some investigation:
Dump method: 3.71 M33 (or Dark_AleX 
)
Output disc Image: 636.614.656 bytes
Usefull info:
LBA :16
0000 : 01 43 44 30 30 31 01 00 50 53 50 20 47 41 4D 45 .CD001..PSP GAME
0010 : 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
0020 : 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
0030 : 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
0040 : 20 20 20 20 20 20 20 20 00 00 00 00 00 00 00 00 ........
0050 : 40 BE 04 00 00 04 BE 40 00 00 00 00 00 00 00 00 @......@........
0060 : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0070 : 00 00 00 00 00 00 00 00 01 00 00 01 01 00 00 01 ................
0080 : 00 08 08 00 EE 00 00 00 00 00 00 EE 12 00 00 00 ................
0090 : 13 00 00 00 00 00 00 14 00 00 00 15 22 00 16 00 ............"...
00A0 : 00 00 00 00 00 16 00 08 00 00 00 00 08 00 69 06 ..............i.
00B0 : 1C 11 38 19 24 02 00 00 01 00 00 01 01 00 20 20 ..8.$.........
0x04BE40 * 2048 = 636.616.704
Filelist:
PSP_GAME
UMD_AUDIO
UMD_DATA.BIN
UMD_VIDEO
PSP_GAME\ICON0.PNG
PSP_GAME\ICON1.PMF
PSP_GAME\PARAM.SFO
PSP_GAME\PIC0.PNG
PSP_GAME\PIC1.PNG
PSP_GAME\SND0.AT3
PSP_GAME\SYSDIR
PSP_GAME\USRDIR
PSP_GAME\SYSDIR\BOOT.BIN
PSP_GAME\SYSDIR\EBOOT.BIN
PSP_GAME\SYSDIR\UPDATE
PSP_GAME\SYSDIR\UPDATE\DATA.BIN - zero size
PSP_GAME\SYSDIR\UPDATE\EBOOT.BIN - zero size
PSP_GAME\SYSDIR\UPDATE\PARAM.SFO
PSP_GAME\USRDIR\MODULE
PSP_GAME\USRDIR\MOVIE
PSP_GAME\USRDIR\SOUND
PSP_GAME\USRDIR\MODULE\audiocodec.prx - zero size
PSP_GAME\USRDIR\MODULE\libatrac3plus.prx - zero size
PSP_GAME\USRDIR\MODULE\mpeg.prx - zero size
PSP_GAME\USRDIR\MODULE\mpegbase.prx - zero size
PSP_GAME\USRDIR\MODULE\videocodec.prx - zero size
PSP_GAME\USRDIR\MOVIE\menu.pmf - zero size
PSP_GAME\USRDIR\MOVIE\movie.pmf - zero size
PSP_GAME\USRDIR\SOUND\menu.at3 - zero size
UMD_AUDIO\CLIPINF
UMD_AUDIO\ICON0.PNG
UMD_AUDIO\ICON1.PMF
UMD_AUDIO\PARAM.SFO
UMD_AUDIO\PIC0.PNG
UMD_AUDIO\PIC1.PNG
UMD_AUDIO\PLAYLIST.UMD
UMD_AUDIO\RESOURCE
UMD_AUDIO\SND0.AT3
UMD_AUDIO\STREAM
UMD_AUDIO\CLIPINF\00001.CLP
UMD_AUDIO\CLIPINF\00002.CLP
UMD_AUDIO\RESOURCE\EN100000.RCO
UMD_AUDIO\STREAM\00001.MPS
UMD_AUDIO\STREAM\00002.MPS
UMD_VIDEO\CLIPINF
UMD_VIDEO\ICON0.PNG
UMD_VIDEO\ICON1.PMF
UMD_VIDEO\PARAM.SFO
UMD_VIDEO\PIC0.PNG
UMD_VIDEO\PIC1.PNG
UMD_VIDEO\PLAYLIST.UMD
UMD_VIDEO\RESOURCE
UMD_VIDEO\SND0.AT3
UMD_VIDEO\STREAM
UMD_VIDEO\CLIPINF\00001.CLP
UMD_VIDEO\CLIPINF\00002.CLP
UMD_VIDEO\RESOURCE\EN100000.RCO
UMD_VIDEO\STREAM\00001.MPS
UMD_VIDEO\STREAM\00002.MPS
Disadvantages:
- wrong image sector count. 636.616.704 != 636.614.656
- wrong PSP_GAME content
-------------------------------------------------------------------------------------------------------------
Dump method: UMD DAX Dumper Beta 0.2 by Dark_AleX
Output disc Image: 905.314.304 bytes
Usefull info:
LBA :16
0000 : 01 43 44 30 30 31 01 00 50 53 50 20 47 41 4D 45 .CD001..PSP GAME
0010 : 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
0020 : 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
0030 : 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
0040 : 20 20 20 20 20 20 20 20 00 00 00 00 00 00 00 00 ........
0050 : 80 00 02 00 00 02 00 80 00 00 00 00 00 00 00 00 ................
0060 : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0070 : 00 00 00 00 00 00 00 00 01 00 00 01 01 00 00 01 ................
0080 : 00 08 08 00 92 00 00 00 00 00 00 92 12 00 00 00 ................
0090 : 13 00 00 00 00 00 00 14 00 00 00 15 22 00 16 00 ............"...
00A0 : 00 00 00 00 00 16 00 08 00 00 00 00 08 00 69 06 ..............i.
00B0 : 1B 15 20 2D 24 02 00 00 01 00 00 01 01 00 20 20 .. -$.........
0x020080 * 2048 = 268.697.600
Filelist:
PSP_GAME
UMD_AUDIO
UMD_DATA.BIN
UMD_VIDEO
PSP_GAME\ICON0.PNG
PSP_GAME\ICON1.PMF
PSP_GAME\PARAM.SFO
PSP_GAME\PIC0.PNG
PSP_GAME\PIC1.PNG
PSP_GAME\SND0.AT3
PSP_GAME\SYSDIR
PSP_GAME\USRDIR
PSP_GAME\SYSDIR\BOOT.BIN
PSP_GAME\SYSDIR\EBOOT.BIN
PSP_GAME\SYSDIR\UPDATE
PSP_GAME\SYSDIR\UPDATE\DATA.BIN
PSP_GAME\SYSDIR\UPDATE\EBOOT.BIN
PSP_GAME\SYSDIR\UPDATE\PARAM.SFO
PSP_GAME\USRDIR\MODULE
PSP_GAME\USRDIR\MOVIE
PSP_GAME\USRDIR\SOUND
PSP_GAME\USRDIR\MODULE\audiocodec.prx
PSP_GAME\USRDIR\MODULE\libatrac3plus.prx
PSP_GAME\USRDIR\MODULE\mpeg.prx
PSP_GAME\USRDIR\MODULE\mpegbase.prx
PSP_GAME\USRDIR\MODULE\videocodec.prx
PSP_GAME\USRDIR\MOVIE\menu.pmf
PSP_GAME\USRDIR\MOVIE\movie.pmf
PSP_GAME\USRDIR\SOUND\menu.at3
UMD_AUDIO\ICON0.PNG
UMD_AUDIO\ICON1.PMF
UMD_AUDIO\PARAM.SFO
UMD_AUDIO\PIC0.PNG
UMD_AUDIO\PIC1.PNG
UMD_AUDIO\SND0.AT3
UMD_VIDEO\ICON0.PNG
UMD_VIDEO\ICON1.PMF
UMD_VIDEO\PARAM.SFO
UMD_VIDEO\PIC0.PNG
UMD_VIDEO\PIC1.PNG
UMD_VIDEO\SND0.AT3
Disadvantages:
- wrong image sector count. 268.697.600 != 905.314.304
- wrong UMD_AUDIO and UMD_VIDEO content
-------------------------------------------------------------------------------------------------------------
Conclusion:
both methods produced wrong images - so we need to pause hybrid disk dumping until Dark_AleX or someone else - creates better dump programm