Cpdunn, yes that's right. When the record is playing, the arm tube should be level with the record surface. But this is only the starting point. From there, you must tune it in by ear, using the method I described above. Some cartridges like a small amount of Positive VTA, which has the pivot end slightly higher than level, and some carts like a slight amount of Negative VTA, which has the pivot end slightly lower than level. You have to find what your cartridge likes.
Regarding the 180 gram LP's, this can change the VTA enough to change the sound of the system. This is why many audiophile tonearms have adjustable VTA, and some have adjustable on-the-fly VTA, while playing. It is due to the thickness of the record, and other records all have varying thicknesses too, so your VTA will change some with each record you play, and the sound of the system will change slightly also. You do not have to re-set the tracking force when changing VTA, unless you accidentally knock it out with your hand while doing the VTA adjustment.
Regarding the 180 gram LP's, this can change the VTA enough to change the sound of the system. This is why many audiophile tonearms have adjustable VTA, and some have adjustable on-the-fly VTA, while playing. It is due to the thickness of the record, and other records all have varying thicknesses too, so your VTA will change some with each record you play, and the sound of the system will change slightly also. You do not have to re-set the tracking force when changing VTA, unless you accidentally knock it out with your hand while doing the VTA adjustment.