I drove all three models, and the SH-AWD one was by far the best.
The I4 with that stupid front collision alert lighting up a big orange brake sign on the dash was pathetic, lighting up at every traffic light as you brake to a stop behind a vehicle in normal fashion. Oversensitive? You bet. The Phat size combined with frenetic engine and DCT was unpleasant - by comparison my old Legacy GT is serene and much, much quicker. Then the TLX went on a weird jag where rolling along slowly and going to make a left turn across traffic, it couldn't find a gear. There's me pumping the gas, nothing. Finally caught and the salesman stopped shouting. The oncoming traffic was bearing down. Nasty.
He apologized for the stupid car's behaviour, and I went to the dealership GM and complained. The salesman, an ex-mechanic backed me up. Ridiculous. So then they wanted me to try a V6 FWD. Much nicer at first. But every time you goosed it from a light, the right front tire howled as rubber burned. Useless. On the highway, I detected a cyclic vibration that shook the whole car at 110 kph. Salesman agreed again. and it wasn't wheels either. Zero for two.
The 9 speed auto acted only slightly better than in the Chrysler 200 - this is a tragically awful transmission.
Three weeks later, a SH-AWD came in and I drove that. Much better except for the transmission, so I tried out a few curves I knew. Tire squeal! Don't even get that on snow tires in the LGT. I mean, just ridiculous.
Don't believe me? Go to acurazine.com, and these shortcomings are documented by others, who also have had myriad other problems. This is a tragically underdeveloped car. It is not even a minor competitor for a six-year old Legacy GT. It is tragic.
Right after the SH-AWD, went by the Audi dealer and drove an A3 2.0T. So much better, I laughed out loud. Responsive, quick, decent corner-carver. Just a bit too much money for decent spec. I'd stretch if it were better than my LGT, but I'd call it a draw, so no dice. No complaints on Audi forums - initial quality thus 100 times better than the TLX.
I'd sum up the TLX V6 models as good-riding quiet cruisers with a Tokyo-by-night suite of electronics, baffling operation of same, a great V6 engine, fair assembly quality (all 7 on the dealer's lot had misfitting driver's doors at the top at the B pillar. Identical misassembly - there's the consistent Honda production methods for you which even reproduces consistent errors).
In addition, all of them had bad orange-peel paint. A big fat turkey as they stand. Not competitive.