I'm not a lawn professional , but I do have a lot of property, about 3 acres, that I keep in good shape. I don't do any of the steps involved in keeping my place trimmed in one day rather it is several days of moderately hard work. The last thing I do is use my string trimmer. I purchased a Troy Bilt 4 cycle about 10 years ago give or take a year or two and it has been the best trimmer I ever used. It does seem a little heavy, but it starts first pull every time year after year and has plenty of power for my needs. The only problem I have had is the kill button doesn't always work, not big deal considering how old it is and the many years of trouble free service it has given me. If it quit working I would not hesitate to buy another considering my good luck with my current one. I had the same feeling for my Kohler powered lawnmower, but the second one self destructed after just 46 hours of use. I see that your not the only one that feels the way you do about Troy Bilt 4 cycle trimmers. What has been your experience that makes you feel that way? I know you don't think it is worth the time to discuss so I won't reply if you'll just tell me your side of the story.
You must have a rare one indeed as I went through no less than 3 Ryobi 4 cycles in about 3 years. Clutches wore out, carbs were hard to start, and worst of all it really aggravated the neuropathy in my hands as they run really rough. Pick up and try a good 2 stroke Husky/Stihl (the FS94R is probably the best lightweight 2 stroke out right now) or a 4 stroke Honda, you'll find they're lighter, easier to start, have much more power, and run much smoother...