Pros: Works fine and very good price if you consider the other prices in USA.

Cons: I wasted so many hours to figure out because the software that comes with CD did not work with my Omnia with Windows Mobile 6.1 professional.
I got
OBD Gauge 1.1
Dana Peters
http://www.qcontinuum.org/obdgauge/
Microsoft .NET Framework 3.5 Service Pack 1
http://www.microsoft.com/downloads/details.aspx?FamilyID=ab99342f-5d1a-413d-8319-81da479ab0d7&DisplayLang=en

Other Thoughts: If this unit had LED, it would be much better. I can tell if it is working somewhat or not.
I might put LED by myself.
I found documet about ELM327
http://www.elmelectronics.com/DSheets/ELM327DS.pdf

Bottomline: I learned about ELM327 very well thanks to incomplete software.

Pros: -Good price
-Small
-Seems sturdy (although I'd like to take it apart and see the inside)
-Software is better than I was anticipating

Cons: -Might be too big for some cars? I haven't found one that has any issues though
-Some software idn't want to connect faster than 38400bps, but I didn't try very hard.

Other Thoughts: It's ELM327, so there's a wide range of software that will work with it.
The code for pairing is 0000.

Bottomline: Buy it. It's useful, and cheaper than you'll find a simple standalone code reader (if that's all you want, maybe another product here is for you). I always have a laptop or my Nokia n810 (Carman works wonderfully with this), so I'm fine with it lacking a display, etc for the added features.

Pros: This is by far the cheapest by far I found. Elsewhere I've only found this unit for at least a hundred dollars.

Cons: Software it comes with doesn't seem to be at all that sophisticated. Also the company is not around to support it as well.

Other Thoughts:

Bottomline: I use this with Carman on my Nokia tablet in my Pontiac G6. In certain review videos I've seen this to be pretty slow for some reason, but on my car it's near instant. I think it depends on the speed of the CAN bus of your vehicle, but on mine it's near real-time. Definitely recommended if you have a newer OBD-II vehicle, but you will have to bring your own software.

Pros: This product is easy to use... Just plug it in your OBD plug, activate your BT non your computer, install the softare, et voila!
It's a generic chipset so it should work on every car using OBD protocol.
Gives basic informations about your car such as engine RPM, speed, coolant temperature...

Cons: It's a generic chipset! Don't expect to get everything from your car.
I have a 1998 Dodge Neon and I can only retrieve the engine RPM, speed, coolant temp and some other things...
But I can't get it to "monitor all". I can't retrieve the fuel tank level for example.
Maybe a little slow... RPMs are updated every second approximately.

Other Thoughts: As I had some problem using it with my laptop, I had to use it through my PDA...
I connected the device to my PDA by BT. Then I installed GpsGate on my laptop and PDA. This software sends what it reads on your PDA serial ports (GPS, Bluetooth, ...) to your computer. Finally it writes data to virtual serial ports on your computer.
Just configure your OBD software to use the virtual port, and you're set!
But it is still slow...

Bottomline: Good product. Does its job.
It's not "complete", too generic, but you've got what you paid: an OBD reader and error code flasher.
Buy it if you just need basic information about your car.