I'm seriously looking at purchasing a Technics 1200GR TT. I like the idea of pitch control. Many years ago, owning both DD and Belt driven turntables, I always felt the DD seemed more precise. Maybe due to the strobe platter edge. A couple of questions: 1. how does belt wear effect speed accuracy? How long should a typical belt last? 2. how does one hook an external speed control to a typical TT? 3. Is it a myth that DD turntables are more speed stable?