I am currently considering getting a new saw. I have a husky 51 which I purchased 10 years ago. It still runs pretty good and I have been very happy with it. I just started burning wood this year and figure I'll be cutting about 5 cords per year (more this year so I can be a year or two ahead). I like new toys and have been thinking about getting a second saw. So far most of the wood I have got has been log length that I have to cut up at someones house and most has been 10" to 20 " trunks, with a few larger ones. The 18" bar on the Husky 51 has been able to handle it fine so far and I don't anticipate felling a lot of trees. I am wondering how much more power/speed I will see with the 5100 and then is the 6400 worth the extra $100 over the 5100. Thoughts please - I know you guys like to spend other people's money so your advise would be great. Larger is usually better but $100 is still a hard earned $100. Thanks Eric