I recently bought a string trimmer at Walmart. There were several very
similar units to choose from, and I liked the way the YardMan felt in my
hands so I bought it.

YardMan YM1500 String Trimmer

# 31 cc engine
# Straight shaft design
# 17-inch cutting swath
# Bump head line release
# Line diameter: .080 inches
# Not attachment capable
# 2-year limited warranty
# Not CA compliant

Unfortunately, it turned out to be a very poor choice.

I had a heck of a time getting it started.
Once started, it idled very roughly.
It was extremely noisy.
It vibrated severely.
It frankly just didn't cut very well.
And it jammed on me within the first 30 minutes of use.

So I emptied the tank and took it back. I looked over the rest of the
models and decided to give a different brand a try. I bought a Snapper
S31SST String Trimmer.

# Quiet-running 31 cc engine
# 17-inch cutting path
# Dual exit bump feed
# Straight shaft
# .080-line diameter
# Not California compliant

As you can see, on paper it seems like a very similar product. Costs
about $10 more.

But....

It starts easily.
It runs smoothly (for a 2-cycle engine anyway).
It's noisy, but it does not vibrate.
It cuts very well, even at idle speed. (It is supplied with a star
shaped string, which is much more effective than the round ones.)
And it has never jammed. Looking at the head construction, I can't
imagine how it ever could.

Just thought I'd post this in case my experience might help anyone else.
The Snapper seems to be a very well made unit.