If you get a used Subaru and one day you have AWD issues (center diffs locking up etc). it's not always as bad to fix as you'd think.
More than one specialist workshop around that will do exchange viscous couplings for reasonable prices.
For the autos, you can buy centre clutch plates and change them yourself with hand tools, patience and a tech manual.
Regular transmission services highly recommended to keep fluid clean.
Head gasket issues on high mileage EJ's are common. This is because people are fuckwits.
Coolant changes /flushes are important. As mileage gets higher a new water pump is a must.
Skipping oil changes is dumb. Adding an oil flush chem or hydraulic lifter cleaner once or twice a year will keep things running nicely.
Rocket cover gaskets often leak - not the end of the world to change.
Yes they are complex cars. But if you accept that they require more maintenance, more often, they can be fucking awesome.
(Like a Yeti?... Or a Specialized..?)
Paradoxically, although there are some complexities, thanks in large part to their WRC involvement Subarus are designed so they're not absurdly difficult to work on - even stuff like head gaskets (pretty awkward on the flat engine layout) can be done without hauling the engine out (been there, done that!).
Early (1996-about 2007) EJ25s in particular were somewhat notorious for head gasket problems, but given the family design it's not implausible for the smaller engines to also suffer. There seems to be little consistency in when they go.... some can be little more than 100k, others will go much longer (mine went around 420k, one was likely the result of being disturbed by some other work I did, the other apparently went in sympathy all on its own).
Although gaskets can go sponateously, more often it's due to overheating from coolant loss. The two likely culprits are a popped radiator (some versions are known for splitting header tanks) or a flogged-out water pump (it has a weep port which becomes exposed when the internal seals are fried). Being all-aluminium, the engine bits are prone to distorting if cooked -> bye-bye gaskets.
The flat layout is prone to collecting oil gunge, so you really want to do oil & filter changes around every 5000km, 7500 tops. With the slightly jacked-up Forester, Outback & XV models it's piss-easy because you can do the filter without even needing to jack the car up. Unless you're really fat.....
Timing belts can be over-run recommended intervals by a fair margin, just pop the covers off & check for wear/cracking - cracks along the belt are OK, cracks across the belt are not. For EZ series 6-cyl motors, these have chain-drive for the camshafts. Like bike chains, these wear with use; as the chain wears the timing will go out of whack, and when really worn there's a risk of the pistons crashing into the valves, and that ain't pretty! So the chains on the EZ motors really need to be done on time!