No. If you read my post I have said that Subaru made the only logical choice. They increased displacement to get power out of crap gas. In my opinion this is the reason the US gets the 2.5 turbo and no other country does. This is a great step forward for that purpose.

2.5 ltrs is a great step backwards for someone wanting to make big power on a tuned engine. Its a fact of life that you need octane to make power. This becomes a huge crutch for people with large turbo swap WRX's in the US. Most of us have to purchase race fuel to make big power. But, If you are going to purchase race fuel and you are wanting big power then RPM on a smaller motor with a shorter stroke is the way to go. I dont have to be the one to explain this. Its been explained over and over in racing history. Recently some of us learned this by watching people around the world produce over 1000hp from RB motors in skylines. The strongest Rb's where all destroked. Spinning to 11,000 rpm has far better gains then stroking the motors to 2.8 or even 2.9 ltrs.

I only bring this up because 2.5 turbo EJ's have been done many many times and they fail to make more power then 2.0's because of the cyl heads. The 2.5 is a design limit engine. The engine was designed as a 2.0 and pushed to larger displacement over its life. What I hope (and nobody knows) is that Subaru went with a new head casting that will support the power we want. If they used the same head castings that they have for years and years we will probably be disapointed once we get the motors past 300-350whp.

AZScoobie, I don't agree on the EJ25 STi motor being a step backwords. Sure its not as capible of being wound out as the EJ20, but according to my rough calculations it was something like 10+K rpm that the EJ20 would need to spin to equal the same stress as a b16 at 8K. The STi EJ25 should be good for 8K easy, with the rods and valvetrain being the limits again like any subaru motor. The extra displacement is nice to get bigger turbos to spool and from surging. Of course like you said the effective head flow takes a hit thanks to the longer stroke, and the detonation resistance is a bit lower thanks to the larger bore. The MAIN issue I can see though is that the cams availible off the shelf will all be too small for a EJ25 turning big RPM with a big turbo.

But seriously, we all will find out the capabilities/limits of the STI soon enough. Here are just a couple of my thoughts. Take them how you want.
-In theory the larger displacement should make/have more power potential.
-But this is a new engine and needs to prove itself. I don't care if people say " but the 2.5 has been around for years!" You're kidding your self. There is nooo way subaru just took the good ol' 2.5 and threw a turbo on it, and hoped it would last through the warranty period. So we'll have to see.
-To counter the above statement: This is Subaru we're talking about. So maybe they did just throw a turbo on a 2.5. ***just kidding*** No flames please. You all need to lighten up.
-Don't forget that it's torque that brakes trannies, and the 2.5 makes plenty torque. Oh yes, the 6 speed can break. It'll take more. But how much? I'm sure we'll find out.
-Torque = great burnouts, HP wins races.
-I don't want to rag on the STI. I love the car. I just wish it came over with the proven 2.0 .
-Time will tell. I hope the 2.5 turns out to be as strong/reliable with the aftermarket as the 2.0 has already done.

PS - I must hand it to mitsu though. The 4G63 has proven over the years to be an incredible motor.