How do you like the car besides the sound system??? If that's not too far off topic...
Although I LOVE the techno goodies of the TSX, one of the big reasons I "downgraded" from the TL was to get a smaller engine that saves money on gas and a generally smaller car because I don't need the space.
My 2006 TL had a 3.2L 258HP SOHC V6 with a 5-speed automatic. This engine was sublime. If gas prices weren't so high it wouldn't be so bad.
My new 2009 TSX has a 2.4L 201HP DOHC i-VTEC inline-4 with a 5-speed automatic. The shifting is rougher on this engine. But, it's a little peppier off the idle. Although my manual says I need to use an octane of 91 or higher, the dealer says because it's a 4-cyl. I can get by with 87 octane.
Although the cabin space is smaller than the TL, there's more room in this latest TSX compared with older TSX models. I hardly fill the car with people anyway. There's basically less leg room for the rear seats compared with the TL. But, it still feels roomy to me. I mostly drive alone. Just as long as you don't have to drive basketball players every day, I think it's fine. And because the size of the TSX is smaller than the TL, there's a better turning ratio. I had a hard time making wide turns and quick cuts with the TL. It was kind of like driving a mini-tank.
Trunk space is pretty good considering it's smaller than the TL. One thing I love about the trunk now is that it has a better system to catch rain that collected on the top of the trunk. With the TL, if I opened my trunk too fast, the water would go in.
Another thing that came with the Technology package is a GPS Navigation system which I absolutely LOVE. Even on a small island like the one I live on, it's still very useful. If I were on the mainland, I could also get real-time traffic and weather reports (it's not available in Hawaii because it goes through XM Satellite). And it also comes with a rear camera when you shift into reverse. It's a great safety feature.
If you have any other questions about the TSX, feel free to ask!