its half half.
i prefer to jump out before getting to a fight scene, and going in guns blazing. rather than plowing through the middle hoping to get some kills... but thats just my personal pref, i find it more fun that way.
as for being on the recieving end, sometimes it can be fun to play the matador against a car trying to run you over.
but it can also piss you right off when you're in the middle of an epic dual, after a 30 minute chase thought the whole city, and you're about to finish the guy off, and out of the blue some guy runs you over.
but the worst is when people have modded their cars to drive at 100,000km/h and kill you in one hit, or send you flying half way accross the map... you can't jump out of the way of those kills.
thats my $0.05