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.

Pros: Cheap for ELM with bluetooth
Small/portable (no long or awkward cables)
BT range is long enough. (Laptop, garage, and my n810).
Does the basic OBD functions well

Cons: No documentation (including the internal ELM327 of which there are a few DIFFERENT versions or the BT passkey of 0000, or what the leds signify)
The particular ELM327 as implemented can't do ATMA (monitor all) with headers on for very long a not-very-heavily loaded J1850 bus. I don't know what baud rate it uses to connect to the BT, but I have a different ELM that is able to do this without a problem (38400 v.s. 9600 baud jumpered). A more expensive device which does BT OBD which emulates the ELM327 and adds a lot of features is easily able to do this.
Gets multiple responses for a request (which can confuse things especially with the headers off)

Other Thoughts: Works adequately for basic OBD-II functions (though the multiple responses are annoying)

Bottomline: Very good for basic use considering the compact size and low price.
Look for something more advanced if you need to go much beyond the basics.

Pros: Relatively cheap and working well. Has Bluetooth connection, so not only you get an OBD interface, but it is also wireless. Comes with Desktop and PDA software on a mini CD. Build quality seems good, the plastic housing is strong. It works with my European 2004 Corolla.

Cons: The PDA software cannot connect to it, but maybe it's my fault. The device is on the big side, but it does fit my car. Check the space around your car's OBD connector and remember that this thing's handle part is bigger than the connector part (but the connector is ok) - check the specs and the pictures on DX.

Other Thoughts: The interface has the ELM327 chip. This means that you don't have to mess with the protocol inside the car's ECU, you can give simple commands to the dongle's ELM chip, and it will talk to the ECU for you. Very convenient. The chip has an actual command interpreter inside, so, if you manage to set up a serial connection to the dongle (through Bluetooth), you can "talk" to it with HyperTerminal. See more details and lots of info on how to "talk to the vehicle" using this product's internal ELM327 chip here: http://www.elmelectronics.com/DSheets/ELM327DS.pdf .

Bottomline: If you need an OBD 2 interface, buy it. It's more expensive elsewhere. I would have actually preferred to have a cable to it (easier for development) but Bluetooth is more elegant. It does have a miniUSB connector, maybe I can use it for wired connection.

Pros: •Plugged directly to and fed by OBD II connector
•Compatible to lots ELM-327 application software
•Was running 15 min after Bluetooth Win Vista Install
•The software accompanying the unit is quite useful and easy to use
•Supports bluetooth connectivity
•The price! No shipping costs!

Cons: •Might be difficult to connect on some cars because is a wider / broader than a standard OBD-II connector
• I am still trying to make it work on a Chevrolet CAN bus, it is probably my mistake.

Other Thoughts: An OBD-II extension cable should be provided as an option

Bottomline: I do not regret buying this as this is the cheapest car scanner one can possibly get. This is a good start for people who hasn't purchased a auto scanner yet and it is highly recommend!