I purchased four of these in 2006, and a further 8 since (total 12). These PARs are good value for money for getting some coloured light in to small areas, and cannot be beaten for the price. However, for larger areas, or more serious use than discos or bands in small rooms, they fall short - as you would expect.
Their design was changed slightly after 2006 to give a taller yoke (this is the bracket they hang on). The extra length means you can now angle the unit straight down without the DMX cables getting in the way. Early units also suffered from dry solder joints, meaning certain strings of LEDs would stop working. This can be solved by taking the panel out and finding the 'dead' LED - either re melting the solder, or bridging the LED out. If under Thomann's 3 year warranty period, they will send new panels.
Stand alone and sound to light modes are useful.
-The PARs will only address up to DMX 128. So you can't use them with higher addresses.
-They are not very bright
-The beam angle is not very wide. Using frost to diffuse the beam reduces the light output
-The colour frame is meshy, and that further reduces the light output
-Over time, the yoke bolts and cable gland can work loose and will need tightening
-Dimming curve is poor
-As there are lots of LED sources, you get colour fringing/shadows
-You cannot make a decent white
-There are 4 fuses behind the LED panel which protect the LEDs. Sometimes these can blow, taking out a whole colour, but can be replaced.
However, these are designed and built to a price, and for that price they are good units, and cheap enough to be abused and thrown in and out of car boots!