Indeed, I am a GP2X fanboy, self-proclaimed.
A couple of their points arent complete bull, and most of them have at least SOME basis in reality, however, I wouldn't call it a fair review overall.
They certainly did not really think the battery thing through. Example: I bought 8 2500mAH AAs for ~$15USD. Fully charged, they give me between 4 and 5 hours of runtime, from what I've seen, which appears to be on par or better than PSP battery life from what I've heard. The power went out in my apartment for about 8 hours last week, so no TV, consoles, PC, etc. I quickly picked up my GP2X and happily began gaming. A few hours later, the batteries died (the set wasn't 100% charged when I started). Had I a PSP, a secondary battery would be $50+ USD. However, I had 3 sets of backups, and quickly poped in another set, and continued.
Then, going home for the holidays, I was traveling for ~9 hours. No PSP battery could last that long. But with 2 sets of rechargables (4 batteries), I was able to have gaming goodness for my trip home. For the cost of a PSP "value pack" (which I consider a contradiction, personally, but I'm biased), I got my GP2X, 4 sets of batteries, and my 1 GB SD card.
It isn't as bad of a review as many people on this forum are making it out to be, but I still wouldn't call it a completely fair review