Telarc 1812 revisited

I've posted several threads about the trackability of this record and have received many scholarly answers, with emphasis on physics, geometry, compliance, weight, angles,price and all sorts of scientific explanations about tonearms, cartridges, VTA, etc, etc. Let's cut to the chase: I have a 1970's Pioneer 540 in the garage I bought for $5 at a thrift store plus an Audio Technica cartridge for which I paid $30 This combo. tracks the Telarc 1812 perfectly without problems while my $4000 Rega and $1200 Project bounce out of the grooves.. I'd really finally like to get some explanation and resolution as to this discrepanccy