A mate owns a B4, has had a few things done like ecu remap to try and minimize the flat spot. Have looked at the dyno charts and it is still there - just more power all round. Funny thing is in stock form he had to get the engine rebuilt after just 10,000 k's - big end bearing. The guy at Subaru docklands said he was under the impression that they had not been de-tuned very well for our fuel. Also had to get the gearbox rebuilt after smashing a syncro not too long after that.
Other mate has a 98 WRX - 40,000 k's following a decent track day out at winton saw a gudgeon pin fail - out came the engine for a full rebuild, also got the gearbox and clutch done at the same time. He does drive it pretty hard, and John Bowe gave it a good fang around the track that day - but once again not good news for suby warranty claims dept.
Still love the rexies, but I am way happier with the over engineered gtr in the driveway.