I have an ST550, primarily to replace an AD3000 and to use it with a 36V actuator and corotor. In terms of price, it's very good value when you look at all the features. The PVR works well and the blindscan is more flexible than most receivers on the market since the v50 and v60 updates. It's also popular with those who are willing to void their warranty and install the hacked firmware which gives the same amount of channels as a Dragon CAM.
However, it's no replacement for the Echostar IMO. The positioner software is poor, only presenting you with counts as it moves from one sat to another, and no graph showing relative postions. The autosat feature, which calculates the positions of the sats using the east, west and mid sat, is also poor and usually too far east or west by a large number of counts. I also find that the receiver often doesn't come back to the exact position for a sat and you need to continually readjust positions.
The polariser part is also very awkward requiring you to setup a wideband LNB as 4 separate LNBs and even then the blindscan function doesn't work properly with a polariser. The receiver also requires that + skew as V and - as H.
I have also been unable to get the Transponder editing software to work with Satcodx files.
Overall, the ST550 is very good value for the price when you look at the hardware side, but the firmware needs an overhaul before you could consider it as a high-end receiver.
