Stefan congrats on the MBP, was looking at them in store the other day and they're beautiful
Regarding your tracking, I have a Nexstar also and here's a couple of tips I've picked up along the way...
* Perform either a 2- or 3- star alignment with a high-ish magnification eyepiece (reticle better) to centre/align the stars as accurately as possible. I've had some success with planetary viewing with only a solar system align on the subject, but the Moon is least good for this because it moves so fast
* check your goto approach settings - you want your final goto approach to an object to be the same as the direction of motion of the object to minimise the effects of slackness in the gears. Check in your scope setup that the azimuth goto approach is negative. The best setting for the altitude approach would depend on the balance of your scope - my SCT is back heavy, so I use negative approach
* to minimise the effect of slack in the gears, adjust the object in the view manually with the direction keys depending on the objects real direction of motion... for example, if the object is in the north and east of the meridian then move the object away so that to centre it again you need to move the scope with an up and left motion (note this is actual motion, not through the eyepiece), or down and left for west of the meridian. The left and right will need to be reversed if you want to track an object in the south.
Apologies if you've tried all these already, in which case I'm stumped
