If you like Fall Out Boy - chances are you'll like this. Paramore blend pop-punk and emo together in a similar way, making them very enjoyable to listen to. Particular favourites of mine would have to be "Pressure" and "Conpiracy", and all of the other tracks also have clearly had a high standard of effort, passion and talent put into them. Personally, I love it.
Technically, this album is brilliant. Catchy lyrics, musically good, so why no 5th star? Well, chances are, if you like Fall Out Boy you probably have a whole bunch of other records like this right now. If they didn't have a girl as a singer, they would not stand out from massive influx of American pop-punk-emo bands who aren't old enough to drink. It slips a little too close to cliche-emo at times, eg, on "Never Let This Go" the first line "maybe if my heart stops beating it won't hurt this much" is, let's say this nicely, far from the most impressive line on the album.
So, should you buy this album? If you LIKE pop-punk-emo, then no. You probably have enough already. But if you LOVE pop-punk-emo, then you'll absolutely love this.