Gotta agree with Debrody. You accept HO's, you're not going to get better in the worse of cases, and are slowing your improvment in the best of cases.
Basically, my reasoning is that, if you HO, it shows that either 1) you aren't confident of your ability to defeat the enemy in a manuvering fight, or that 2) you are confident that your opponent is newer, or just can't aim for hell (else HO just results in a mutual death, or severe damage a least).
If its the first, then the reason for why you souldn't HO are obvious: You don't get better without practice, and the best practice is against those better than you are.
If the latter, then the reason is that you're simply being lazy and don't want to take the time to manuver. Its more courteous, and fun, to manuver for the kill, even if its not nessecary.