You seem to be in a very similiar boat as I am. I currently have an 02 Acura TLS which I really liked. After 15 years 204000 miles it still runs good but I am get wary about a car once it goes this long so I have been looking for a replacement. My preference is for something smaller, lighter, better fuel mileage yet still good performance.
You can even look at my post and and see how my search went.http://www.truedelta.com/Replacement-for-2002-Acura-TL-Type-S/next-car-Q605&v=1
Yes, the Honda Civic (2016) is tops on my list but I have to sit and test drive it. That's something I need to do. I already wrote off the 2012-2015 Civic and the Acura ILX due to a lack of headroom less than 1". However when I sat in the 2016 at an autoshow I had about 4". Its on my list of things to do.
I did test drive a used 2015 Accord Sport and I liked how it handled but I didn't like the feel of the CVT. I think its something that takes getting used to. I did have one with a rental Altima for about a week not long after this test drive and after a day or two I hardly noticed it.
Test Drove a Mazda 3 S GT 2016. That car was great, I just didn't like the "racer" look of the big central tac/speedo. Same with the i model with the big speedo in the middle and the digital tac. This along with the Accord will probably fight with the Civic.
I also test drove a used 2015 Mazda 6 but I suspect it might have been abused, it didn't handle well at all. I'll probably try a new one. That used one had 70K miles on it, so maybe I should give it another chance.
I had a Nissan Altima S 2015 for a week as a rental, that car drove fine and I got great gas mileage with it. The biggest beef I had was with the seats, I found the hyped zero gravvity seats to be uncomfortable for me. Thats why I find the test drive to be important. Personally I think auto "journalists" tend to way overexaggerate how "poorly" some cars drive. I don't find them to be credible anymore as a result. Most of the time their favorites and low on sales and their hated cars are top sellers. It doesn't really matter what anyone else thinks, its how do you feel about it, since you are paying for it and have to drive it everyday for the next decade perhaps. You might find the seats to be comfortable.
I might also suggest a used 2013-2014 Lexus ES350. These can be had for the mid 25 range certified which is roughly what these others are selling for new.