Problem with the straight one is that the hozelock fitting that goes on to it soon starts to wear, then the reel centre fitting itself wears. This is because when you reel out/in the centre is spinning inside the hose fitting. In a very short time this leaks badly, then starts to spring off every time you pull the hose off the reel. There was a lot of complaints about this over on another forum some years ago, which is when the suppliers started fitting and recommending the elbow because the hose doesn't spin on this.