Should i rent Metal Gear Solid 4 from Blockbuster? And if I did, would I have time to beat it in a week?

(Note: When I play games I play VERY frequently - all day - and usuall beat games in less than a week. Examples include:

Resident Evil - 2 days

Resistance 2 - 3 days

Dead Space - 7 days

Killzone 2 - 3days)

So what do you guys think?