Looks wise, both are nice cars. I like the body of the tC more. It just seems to have more "form" whatever that means. You really can't go wrong with either and it all depends on your tastes in the end,
Reliability, once again, straight down the middle.
Now for an SQL system, I can only judge for a tC since I own one. But installing a system in one is very straightforward. No pain in the ***** or anything. The hatch itself is kind of small but its good enough for an SQL system. I fit four 8's in mine. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif One thing that is a ***** about the tC is the rattling though. You are definetly going to have to deaden the shit out of it. But that adds to the fun.
Price/Quality, both good but you definetly get a very good bang for your buck with the tC. Even though they allow no "haggling" (negotiations) on a tC its still a very good value. (They might give you free floormats though. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
Honestly, once you take both out for a test drive, it will be a much easier decision.
From the looks of your posts it does seem that your going towards the Si though, but good luck with your decision.