Well... What do you expect from a battery review.
It does appear to run slightly longer than the default PSP 1000 battery, but then again, I had my PSP since launch and thus it's battery life must have taken a hit during all those years. I believe I was getting about 4-5 hours worth of gameplay with my old battery and I'm probably getting about 7-8 with the new one... Then again it's really hard to anticipate with the battery life estimation changing depending type of usage/brightness settings/clock speed/etc.
Honestly, if you were expecting to play 24 consecutive hours, you'll be dissapointed, but if you just wanted a battery to swap when going extended trips, or one that lasts you longer in between charges to be able to game outside for longer than a few hours at a time, this battery might be for you.
Comes with a few battery faceplates for other PSP models, apparently that battery gives an even better boost to more recent PSPs, so mileage may vary.
Be seeing you.