I got one last week in SLC (bump up from a midsize). I was going to one of our plants which is about 45 miles east of Twin Falls, ID, so it's a bit of a haul (2.5 hours). It's certainly a decent-looking car. As I was walking up the #1 Gold row at SLC, I thought for a sec they'd slapped me in a Jag X-Type for some reason - very similar lights and hood.
Driving - this car's got some nice jump to it...I decided to drive it a little hard through morning SLC traffic on my way out of town, and it performed admirably. Quick acceleration from a standing start, and decent pick-up even at highway speeds. Once I got into more rural areas, I let the cruise take over, and had no problems making my way up through the mountains and into Idaho. Even holding it steady in the low-80s, I was right around 23-25 mpg for the drive, according to the trip computer.
Handling was good...I shot through cloverleaf ramps at speeds that would make a Taurus run crying to Uncle Henry.
I ended up finishing up my work at the plant early, so when I headed back down to SLC, I overshot a little and took I-80 up to Park City. There was some light snow in the mountains, but the car felt firmly in control of the conditions on the interstate as it wound its way up.
The semi-manual shift system responded pretty well...some cars have a decent lag between when you flick the level and the car responds, but the Amanti shifted well. It did automatic downshifting while braking, and also allowed starting out in 2.
Creature comforts - I found the ride and amenities to be good. Stereo was good, although I found the bass was distorting a little bit too much, even at a flat EQ setting. Seats were comfortable for extended drives, and on the colder mornings, the seat warmers were much appreciated. I think the 5-level heated seats might have been overkill, as 1 was undetectable, and 5 might have rendered me sterile if I sat there too long.
Trunk space was decent - I just had my rollaboard, so I didn't strain it, but it seemed comparable to most non-land barge sedans. I didn't have anyone traveling with me, but it seemed like the back seat legroom would have been lacking if someone was sitting behind me (I'm 6'3").
Overall - the car was definitely a worthy upgrade. It's a slightly less-exciting rendition of a Nissan Maxima, which is one of my favorite cars to get from Hertz. In my hierarchy, I'd rank it below the Maxima, but above the Camry and Impala. I'd recommend it.