Pros: It's cheap and may be useful to you. For me the 0/+5V voltage levels are useful for microcontroller interfacing.

Cons: The driver CD did not work on my computer so I could not test the it in Windows. In Linux the device works without a driver but sometimes makes the computer freeze completely (needing reboot) when sending data.
The USB connector is a bit loose and may come off if you stress it. The plastic is soft so it doesn't help the mechanical stability much. I removed the case and added some super glue to the USB connector.

Other Thoughts: The device identifies itself as a PL2303 but when looking inside it I saw a "black blob" which may mean this is not a real PL2303.
The device doesn't use real RS232 levels (+/-12V) but instead 0/+5V from USB. This works for home use, but it may be unsuitable to use this device for really long cables, such as in a server room. Actually this is what I wanted and expected to be able to interface with microcontroller chips without the need for a level converter.

Bottomline: For the price, buy it if you need it. It's a decent product for the low price. But don't use it in a critical work environment.

Pros: Very good product, worked perfectly communicating with electronic equipment, reclosers, energy meters. I also used to update firmware of LCD TV and embedded devices, modems and other, everything worked very well. Even one of the GPRS modem I use, uses the same chipset MAXIM. All very good.
Produto muito bom, funcionou perfeitamente comunicando com equipamentos eletronicos, religadores, medidores de energia. Usei também para atualizar firmware de TV LCD e equipamentos embarcados, modems e outros, tudo funcionou muito bem. Inclusive um dos modem GPRS que uso, utiliza o mesmo chipset MAXIM. Tudo muito bom mesmo.

Cons: The welding tip through USB found weak, but I decided to put a few drops of super glue
A solda na ponta USB achei meio fraca, mas resolvi colocando algumas gotas de super cola.

Bottomline: Considering the value of the product, it is worth comparing here in my country, a semalhante costs about $ 35.00.
Considerando o valor do produto, vale a pena, comparando aqui no meu pais, um semalhante custa cerca de US$35,00.

Pros: - Works with all OS Systems.
- Overall quality build is Good.
- Comes with USB Extention
- Comes with CD with the Drivers for Win XP and Win Vista (Win Vista Drivers works with WIndows 7)

Cons: - USB Extention with low quality build.
- CD must come with something to protect it, that was not, it was only the CD itself.

Other Thoughts: I just think that this product is a must buy to much people that need an RS232 Port and don't have it on computer.
Price is awesome and for all the effects it works great.

Bottomline: Sorry for the bad english cuz im Portuguese

Pros: - Just works within Ubuntu; no drivers needed.
- Driver disk includes drivers for linux/mac/win98, 2000, XP, vista, CE
- USB extention cable included

Cons: - Extention cable does not look like it's a heavy quality cable, it's kinda thin.
- RS232 screws on the connector are hard to turn as the casing of the adapter is really next to the screws
- driver cd contains drivers for other devices, so you have to look for the directory called "(USB-SERIEL2303)"

Other Thoughts: Can't go wrong for this low price. The chip used inside is a PL2303, which is also used in (extremely) more expensive cables like Belkin and Belkin did not deliver Vista drivers on the cd. Even if the extention cable is broken, it can be easily replaced by any other USB extention cable.

Bottomline: Buy this if you need a RS232 connector on your pc as many new computers and laptops does not have such a port nowadays.