Have another question. How do the MG gear trains hold up in the 5985, and how do the electronics hold up in both of these servos. I havent read about very much experience with these yet.
Edwin

yeah fill us in...

They are two different servos entirely. The 5955 is titanium geared and the geartrain lasts practically forever. They develop about 250 ounces of actual torque and are very precise. I just sent six of them in after being involved in a crash in a 40%er. They all came back in fine working order. The only thing replaced was one servo case top.
The 5985 only has about 150 ounces of rated torque and the gears are not titanium. They are metal-geared and surely durable, but will develop play and wear eventually. While I don't have any direct experience with the 5985, I do have experience with the 5945, which is the servo the 85 replaced. It is a fine servo for its price and can be used in anything from a .40 size to a 100cc size with success, but it doesn't center nearly as well as the 5955 and obviously can't be expected to do the same work. I have had both the 5945 and 5955 in various planes over the past couple years and neither have burnt up or stripped on me.
Bottom line: if you want precision and need the torque, go with the 5955. If you are looking for a servo for a 50cc plane or smaller and aren't going to be competing, the 5985 will do just fine.

Thanks. I'm planning on putting them into a GP Yak 54. The 5955's are going on the elev/rud. I was going to use the 5985's on the ailerons. But for a little more, I could use 5955's all around. Guess I'll do that.
Edwin