Actually better than Rec.
I picked up Quarantine on dvd as an impulse purchase as I enjoyed Carpenters performance in Emily Rose... loved it! It had the adrenaline pumping and had plenty of scares.
Bought Rec on Blu Ray out of curiosity and whilst I enjoyed it and respected that it was the original I really thought that Quarantine was a little more stylish and had the better performances on a whole. Also, the ending was much scarier.