They are only as problematic as you make them. I find them to be very reliable.
The person, who wrote these sentences, must lead a charmed life.
I personally have had problems with two different kinds of USB-to-RS232 adapters connected to my Dell laptop running Vista:
1. RadioShack's Gigaware works with my AIM-4170 and the Keyspan won't (please note that W5BIG and I spent days trying to get the Keyspan to work the AIM).
2. Keyspan worked with my Yaesu FT-950 via Logger32 but RadioShack's Gigaware won't.
Figure that conundrum out.
Now, because my grandchildren do their homework on the laptop, I've bought a new HP-Pavilion p6-2021 running 64-bit Windows7 and neither adapter works my FT-950.
Just to comment....I have the latest drivers from the respective manufacturer's website and do pay proper attention to COM-ports, baud-rate, etc.
Interestingly enough, my six year old Dell desktop with its built-in RS232:
1. ran the AIM4170 with no problems,
2. does everything very nicely in Logger32.
Life is too short to waste on getting USB-to-RS232 adapters to function; I'm now shopping for a RS232-card for the HP.
73 Jerry KM3K