high resolution camera make a difference?

["mole" <chromallly@xxxxxxxxx>]

I just bought a DVR with a 160 gig hard drive and a cheap camera
yesterday.  The picture quality isn't all that great.  It's fuzzy.
According to the manual, its effective pixels is 628*582.  Resolution
is 380 lines.  I want to replace it with something a bit better.  The
shop has a bullet type high resolution camera.  Would that make any
difference?  The thing is, I'm only using a regular TV (NTSC) to review
my recordings.  The high res camera has 420 lines of resolution.
Doesn't NTSC TVs have 480 lines of resolution?

Does high-res camera like this take more hard drive space than low-res
ones?