'04 Camry transmission

I have two Camrys, an '00 and an’04. The '00 is the best sedan I’ve ever owned, with light brakes, great steering and suspension, excellent pickup and responsive transmission; at 95,000 miles, it runs like new. So I gave it to my 18 yr. old son and am now driving my mother’s '04 Camry. It’s like night and day–in the '04, the brakes are “heavy”, there is a lag between pushing in the accelerator and actually speeding up, and there is a roaring sound that’s particularly noticeable in the lower gears.

I can live with the roar, but I drive in Northern VA, where your life can literally depend on your car’s responsiveness speeding up and slowing down. The Toyota people replaced the manifold to help the roar (it didn’t) and had nothing to say about the transmission lag. My wonderful regular mechanics played with it a little, but said basically the Camry from '04 on went downhill in quality (Camrys are no longer listed by Consumer Reports as a Best Buy). What did Toyota do to this great car, and is there any way to improve the acceleration response so I don’t get killed in NOVA traffic?

Is this a V6 Camry or a 4-cylinder? The V-6 was not recommended by CR for a few years, but the 4-cylinder has always been on their good list.

Why not just trade cars with your son and drive your faithful '00 Camry again? At only 95K miles it is FAR from worn out. It could easily go three times that far.