I disagree with that so much, I deleted it when I quoted your post.
EJ22t is definitely not the best Subaru engine ever made.
I've owned several high mileage 00-04 Ej25s. Never had coolant leak out the block. They all leaked oil externally. These use the exact same head gasket as the 05-09.
Now, of course, we're talking about ~20 year old engines. There are soo many variables in maintenance and care that have a bigger effect on the future running than any design changes. For example, I have an '02 Outback H6 that's been clearly beat up, neglected, and left for dead, and it has a dead cylinder, at 130k miles. And my daily is a '00 EJ25 with 355k on it, that runs beautifully.