It's a huge hassle to use every day, and it doesn't work with some games. It might make a decent second card to store old saves.
In my initial frenzy to find a memory card for my Playstation 2 when I bought it back in December 2001, I bypassed the Sony memory card in favor of this one to save $15. That turned out to be a big mistake!
Every time you want to use this card you have to load the included Memory Manager disk, press a few buttons, then load the game. This only takes a minute or two, but try telling that to a five-year-old who's screaming to play Jak & Daxter.
Other than the swapping inconvenience, I had no problem using it with the games I'd purchased at the time. (Jak & Daxter, Crazy Taxi, Gran Turismo 3, NHL 2001, Rayman 2) However, the last straw came when I rented Metal Gear Solid 2. It wouldn't work at all. MGS2 couldn't find the card. That was a total waste of a rental. Since I knew that one day MGS2 would be in my collection, this memory card had to go. I use Sony cards exclusively now and couldn't be happier.
The only thing keeping this card from the lowest rating is the compression ability. I rented NHL 2002 to see what I could step up to in the future, and I managed to complete quite a few of the "tasks" to earn "cards". (If you had the game, you'd know what I mean.) Of course, I wanted to save these for when I would own it, but NHL 2002 used 2MB for a game save! I didn't want that around clogging up my card for months. Memory Manage allowed me to compress it to less than 300K, which left me with plenty of room for my other games. For this reason, this way makes it a good companion to the Sony card for game save archival.