Summary:
Excellent machine. Expensive, but you get what you pay for.

Strengths:
Plenty of power. Fairly easy to start. More reliable than the cheaper brands.

Weaknesses:
Black fuel line tends to deteriorate. New green fuel line is much better quality.

Summary:
I have had the FS46 for approximately 4 years, and it has been an excellent trimmer. On average it is used around 5 hours each week during the trimming season, and it still starts up and runs like new. I also have a heavier duty Stihl FS80R Professional trimmer, but my FS46 has been my 'go to' trimmer for everything other than very heavy duty trimming conditions. The FS45/46 Series are excellent trimmers are an excellent choice for normal residential use, especially when you consider their lower cost.

Strengths:
Lightweight, plenty of power to cut through tall grass, the longer shaft (compared to the FS45) is more comfortable for taller users, and it is much more dependable than many other trimmers in the same price range.

Weaknesses:
I haven't had any problem, except for replacing the original 'black fuel line' with the higher quality 'green line'.