Where you on Scoobynet then? I was some year's ago now (same name as on here).
Did love my classic Impreza whilst I had it but it destroyed it's engine twice, gearbox twice, centre diff, rear diff and countless other parts.
It was running high boost but think I just had bad luck with a lot of it tbh. The engine's big end went a month after I bought it in standard guise due to oil starvation after the oil pump failed. Decided to keep it & forked out over 4.5K on a full engine rebuild with lot's of uprated part's.
The engine went really well for awhile, although other parts like the gearbox etc didn't, until one evening whilst on a gentle drive (not under heavy load or high boost) the engine decided to destroy itself again & throw a con-rod right through the side of block.
That was the end of that as I decided I'd had enough of the WRX and moved on to a Civic Type R & now the 350Z. Much happier now.