I have the auto WRX Wagon, and the off the line performance quickly got on my nerves particularly when in heavy traffic trying to make a left hand turn. Waiting for the car to get moving, as traffic approached just felt unsafe. I did the TC conversion and what a difference. Now when I hit the gas, the engine revs for a second to get into the power range and then off you go. The advantage is the engine gets under boost without trying to start moving the car at the same time. Oh, and for a real kick, try break launching. You will take off like a rocket (only with the TC conversion though, not much help without it). I have a spare TC for sale if you are interested. $300 investment so you don't have to go for days without your car, then like me, you pass on the convenience to someone else. Let me know if you’re interested. Also, keep in mind that replacing your uppipe at the same time is much easier as you are dropping the tranny anyway, making the uppipe (a very involved upgrade) much more accessible.

I spent $300 for my TC, had the seller ship it directly to Protorque, had them mod it for the $500 asking price, then bought an STI uppipe to go in at the same time. You can sell the stock uppipe for someone who wants to bore out the cat for a cheap uppipe solution, as well as your core TC. I have the stock uppipe (un-modded) for sale as well if you’re interested for $40. $500 for the install of both the TC and uppipe and the guy had it done in about 7 hours. If you go with the bored uppipe and sell your parts after these 2 mods, you will have invested about $1000.
$500 modification of TC
$500 install if you find the right installer.
The $340 + shipping for the TC and stock uppipe you can get back when you sell yours.

Jason A.