As a Christmas gift this year, I received a Proses LB-902 Rotating Loco Cradle. As stated this tool is supposed to be for use with N, HO and O scale trains. Please see the attached photo if you have not seen one of these.
First, there is some assembly required. There are limited instructions on how to do this. You match parts up as best you can with some pictures supplied on a single sheet. Right away I saw that the rotating gears on the 2 units were out of alignment. This required a small disassembly so that the gears could be matched. It was not difficult, but why??? You will not be able to get full rotation if those gears are not aligned.
The tool comes with four separate jaws to hold your "patient". While I thought this was very useful at first sight, I quickly realized how impartial this really was. The adjustments are made using wing nuts. Four separate wing nuts. Now imagine holding an 8 pound locomotive in one hand while adjusting 4 separate jaws with wings nuts using the other. I eventually got it to hold, but I would have been done with my repair had I just used a foam cradle, before I would have ever gotten this locked in place. At best, the jaws should be spring loaded or ratcheting adjustments. After rotating it a few times, the loco fell out of the jaws. This is simple because it is not robust enough for heavy O scale locomotives. As you can see in the photo, I was only trying to work with an old Atlas switcher. At about $80 with shipping (and that was on sale from $129) this is not a "toss it and move on" purchase.
Overall, if you are working with smaller gauges or just plastic O scale rolling stock, it might be just the right tool for you. But there is no way that it beats a standard foam cradle. 
