I am more comfortable in lefts because NHMS is mostly lefts, and two of the major rights have huge pavement transitions/cracks.
The new NJ place is mostly rights so I should be able to even out both my skill and my tire wear (get my money out of those bitches!
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edit: Also, in general, on the street lefts are higher speed and more sweeping because you drive on the right side of the road here. It is common for people to be more comfortable in lefts for that reason and also because they have less tendency to be blind corners.