My neglect of Orbiter 2010...
I have to confess that I don't use Orbiter 2010, at least, not regularly. I haven't made an effort to move my addons to 2010, and I develop in, and primarily for, 2006P1.
Feel free to hate me. I already do.
Don't get me wrong, I love Orbiter 2010, and the updates to Map MFD, the sky-dome feature, and the ability to code for secondary light sources. Other changes however, I'm afraid to say I'm not too enthusiastic about. Not because I'm trying to be antagonistic or that I disregard the immense amount of effort that has gone into 2010P1, but because, honestly, I find these changes
confusing.
For example, the default fuel and thrust guages level changes from percent and acceleration to mass and thrust. While I'm sure these are helpful in certain situations, in general (I at least) find them to be confusing and mostly irrelevant. Surely, the amount of fuel you have in relative terms is more important than the mass, which is entirely dependant on the vehicle being flown? Similarly, thrust can change with the vessel as well, where as acceleration is a constant regardless of whatever vehicle you fly. In other words, if I want to fly vehicle X Y or Z, I have to study all of it's parameters, and where they sit in the grand scheme of things, and even then it's hard to paint a mental "picture", if you will, of what's going on in relative terms, that are relevant to the ship at hand. Going over a vessel like this is not a bad thing, not at all, but sometimes I want to fly around, and not take things seriously enough to write a multi-page reference list to fly each and every vessel. Not that there's anything wrong with that.
Similarly, I found the inclusion of gigameters to be interesting, but they push the AU measurement into a "zone of impracticality". If metrification was so important, then the AU should be replaced entirely with terameters, especially considering that AUs only take over at the terameter mark. I do find gigameters particularly useful on a smaller scale, since working with such distances in AU is a bit of a pain. In that case, a 50-100 gigameter cutoff to AU might be better, even if it is an oddball number and probably impractical/stupid.
I guess my feature request (or the culmination of my petty rant

), is for these attributes to be controlled by config file, or a menu in the Orbiter launchpad, so that the user can choose what method of measurement (or measurement) they would like to use.
The real reason of course for my neglection of Orbiter 2010, is that it seems to "chug", even though framerate remains steady, for reasons I can't understand. Nevertheless this is (probably) not the place for discussing such an issue, and it likely has everything to do with my substandard machine rather than Orbiter itself.