MC cartridge loading: still baffled


I am using a low output moving coil cartridge- a retipped Linn Troika.  Recommended loading is 100-200 ohms which I have always followed.  My phono pre is an Ayre P-5xe and set to the highest gain.  Years ago, Michael at Ayre said most moving coil cartridges sounded best when loaded at 47k ohm using their phono pre.  I just got around to trying this setting and it does sound more open and better to me.  Lately, I am discovering that much of the dogma that I have been following isn't necessarily correct, at least with my system and to my ears.  Another example I found recently is that my arm/cartridge performs just fine with very little anti-skate force as opposed to just picking a setting equal to VTF as universally suggested.

Back to the loading question:  is the proper loading more a function of the phono pre or the cartridge itself?
jc4659
@millercarbon always disheartening to realize you've got a loose screw!  ;)  I'm going to try the center image test on some recordings that I know to have a dead center vocal image.  I am also OCD about speaker positioning.
Actually Lewm that is Frank Schroeder's method. I prefer to use the HI Fi News test record as it has an excellent anti skate track and both vertical and lateral resonance tracks. But I have noticed repeatedly that once I set up the tonearm with the record the tonearm drifts slowly towards the spindle on a blank record so Frank's method works. 
When using the test record you are using your ears to detect miss tracking.
I can't count the number of screws millercarbon has loose. Setting up a system is simple once you know what you are doing. The vast majority of "tweaking" is mythology. A really good tech can interpret what a client wants to hear into the system's sound. 
Yogi, blank LP is not a good tool for setting AS. The skating force is due to the friction of the stylus as it passes over the vinyl in the groove. A blank LP by definition has no grooves. Therefore, it does not present the same friction related resistance to travel as does a real LP with grooves. This has been stated and restated over and over again on various forums.
While I agree with your conclusion, the number of falsehoods being stated on various forums as facts are as numerous as the grains of sand on a decently sized beach.