To say 'Quarantine' is based on the Spanish classic 'Rec' would be like saying water is based on H20.
'Quarantine' is a solid shocker, but only because it's a virtual carbon copy of the superior Spanish version. 'Rec'
Rec (Single Disc Edition) [DVD] just works better all round for me. The scares are scarier, the special effects more advanced, the acting slightly better and the tension all the more tense.
If you don't like subtitled films, then watch 'Quarantine' as it works well in its own right. If you genuinely want to see the better of the pair, then 'Rec' wins hands down every time (by the way 'Rec 2' is just as good and a neat follow on).
I don't want to go into a Hollywood rant, but 'Quarantine' is pretty lazy. It's like they thought we were somehow too stupid to understand the Spanish version and as such, needed our hands holding tightly through the production of an American re-make. There have been some great re-makes, but the key for me is to do something different to enhance the original. 'Quarantine' adds a couple of very minor changes, but apart from that duplicates the original frame by frame.
Of course, being a copy of a very good film, 'Quarantine' itself is very good; that goes without saying. If you built a carbon copy of the Winter Palace, that too would be an impressive building....you see where I coming from.
Worth watching, but I just had to knock a star off for lack of originality.