I swapped out the stock seats in my 2007 WRX TR for STi Limited seats yesterday. Unfortunately, I do not currently have the wiring to enable the use of the heating elements in them, but I plan on making that happen as soon as I can. I posted a thread here about that issue last week, but I didn't get many answers. If anyone can offer advice on what I need to do this, I would greatly appreciate it.
To get back on topic, I am very happy with the STi seats. They offer a welcomed change in comfort and style compared to the stock seats.
Here are some pictures for anyone thinking about doing this mod:
I hope to find reasonably priced leather back seats some day, but for now I am happy with how the interior looks. The contrast between the leather fronts and the cloth backs looks better than I had anticipated.