despite nothing major went wrong with the car in my ownership I still don't class it as reliable, especially comparing it to a standard 172 but you already know that. I wouldn't "rely" on it to drive me circa 200 miles without something failing. And as you already said to ME before I bought it. You buy a car like that with OPEN EYES as something will indefinitely go wrong.
anyway, one thing that did get me scratching my head was how I opened the bonnet one day and the coil pack had fallen off its mount and dangling just above a boiling hot turbo, luckily there was no damage to it, and I refixed it with stronger bolts. I could only put it down to the sheer engine vibration on those mounts, how it had unscrewed 4 bolts was baffling though. Anyway you got a f**king bargain on that car so be happy. And stop trying to make an honest seller look bad