I have experienced the low rpm lock-up vibration on several different vehicles. They ranged from a suburban, to an intrepid, to a venture van. I assumed it was the lugging scenario as well. I noticed on my test drive that when I really got into it on a ramp getting on the freeway, it felt as if it leaned over towards 70 mph. I didn't want to abuse it too bad because I was wanting the vehicle I was testing, so more than likely I didn't peddle it enough.
As it is past it's warranty break-in schedule I have found that it is very nimble in traffic and has no qualms about going from 70 to 90 in a very short time. Where my other vehicles would have tached up quite audibly (and sometimes scarily) when they found the passing gear, ole MO just grins and glides up to speed, a much more civilized application of power. Truthfully I am unaware if I have felt this vibration---the chevy venture did it every day on my launch off the ramp to go home so I am used to it. I think all of us have to get used to the CVT--it is so radically different to what we have become accustomed to.
On a side note: I had a hemi ram truck that was riding my butt as I was going 85 on the freeway blast off as I pulled over one lane. Ohhhhh, it was loud, boy did those revs hit the sky. I remember doing that in my camaro many years ago. I also remember having the engine spin rod bearings after about 2 years of doing that. That ram really zoomed up—about 200 feet, I waved as I passed him on the right with ole MO tachin just above 2 grand.
