Driven and owned a 2011 Montero and it has clocked about 40k kms already. Scheduled PMS this coming Monday.

Main issues encountered:
1) Rust formation in the fuel neck/tank - check engine lit up and after inspection they found that the fuel neck had rust formation. Blamed the fuel I top up with. Used to use mainly Petron or Shell Diesel only.
Solution: Switched to Euro 4 diesel. been using Seaoil diesel since January 2014. So far no issues with it but since they haven't replaced the rusted part yet, my check engine light flickers on and off from time to time.

2)Suspension - had mine replaced because it had fluid leak when it was just clocking around 15K kms in mileage.
Solution: Driving more alert since then because I think I did ended up going through potholes at speed during carving through Maharlika Highway 2 years ago.

3) Cold start power loss isses - whenever the engine starts after being off for more than 10 hours, you will feel the engine not being very responsive. Problem is more prevalent when using Caltex Diesel.
Solution: Read forums and switched to Euro 4. Problem has not resurfaced ever since.

4) AVT MID Unit freezes up ang hangs after prolonged use (more than 4 hours of continuous use - It also actually crashed and restarted but could not play any digital files on the USB
Solution: Winterpine completely replaced the unit under warranty

5) Alarm too senstive - Leaving the car in any parking area, alarm would immediately blare out eventhough no one is nearby.
Solution: Winterpine checked the sensor setting. Although it was already in the least senstivie setting, the issue was prevalent. They completely replaced the device handling the sensitivity setting

Overall still happy with the vehicle but I do hope the rust formation does not resurface after I am now using Euro 4 diesel.

Also, after switching to Euro 4, I never had any instance of "black soot/smoke" being belched out the exhaust pipes anymore. Greyish (Light to medium) in most cases only after 6 months of exclusively only Euro 4 fuel.