I have one of these walk behind weed trimmers and love it! No weight on my back and shoulders while cleaning long fence rows. They take an extremely heavy string, 155 I think, that cuts well and lasts pretty well. The heavy string is available from other folks than DR, could be cheaper too. Mine is usually one-pull to start, never more than 2 pulls. Pretty easy to manuever. I get a lot of fence done on a tank of gas. The DR folks have a good warrenty, will take them back if unsatisfactory, with paid shipping and if you bought from the website. Not sure about how they manage returns sold thru other places like TSC. They have sales all the time, so you can get them for less than list cost.
I would recommend getting the extra cost mow-ball for the string, so easy to use! Just push in cut length to add new string or adjust the length of strings very quickly. The slotted string holder that is standard can be a bit difficult to change strings on. Husband drops the string holder now and then to clean out trapped weedy pieces that can slow the belt. Easy to do, fast to blow it clean, then put all the bolts back in place.
I do a LOT of fenceline with needing to keep our tensile wire hot. This machine is a blessing. I have tried other makes, but they did not hold up to long running times more than a year or two. Carrying a trimmer for long times is exhausting. Pushing the trimmer never seems like it is hard, though i do get tired lIke any job does to you. DR has greatly improved these machines over the years, since I first got a used one. I decided I needed a Newer model and sold the old one. Love the new one!
DR also has a tractor powered fence trimmer I tried. It did not work well with the tensile wire. I broke it twice, they paid for repairs when I took it in. Same 2 issues both times, with very long wait times at busy repair shop. No use having it if it keeps breaking. So per the warranty, I returned it. I did put it back on the same pallet machine arrived on, bought some super long, heavy zip ties at Home Depot to secure it to pallet. Put it on the Semi they sent and got my money back. Looking at their advertising, all the fences were board fences, maybe I should have figured out it was not meant for wire fences!! Ha ha It was a nice machine, cut weeds well, but there is a learning curve to using it.