The interiors on current Nissans are junk compared to Hondas. I went on a test drive with a friend of mine last year with an Altima 3.5 SE. The plastics were about on the same level as a mid-1990s GM or Ford. The glove box and sunglass holders aren't dampened, and all the switches are very loose and cheap feeling. Nissan uses the same basic interior designs for the Altima and Maxima. Only difference between the cars is available luxury features and size.
I've heard Nissan is vastly improving their interiors for their '07-08 releases.
They make very good motors, though. The VQ series 3.5 V6 is just as reliable as any Honda engine, and much more low end tq.
Nissan has fantastic drivetrains and very artsy style. They improve their interior quality and I'd certainly consider them on the level with any Honda.