I can only speak of the 2.2 with the highest regard. Having owned two cars with this motor it is crazy reliable with only basic maintenance.
My first legacy had well over 200,00 miles on it when I sold it (bought it at 150,000), never had a problem.
My current Legacy with the 2.2 has 140,000 on it (bought at 46,000) with the biggest problem being a failed alternator. Both were/are manuals.
I understand the 2.5s have head gasket problems, but I wouldn't know from experience, just what I have heard and read about.