Mechanically, Porsches now are probably more reliable than they ever have been so I think you have missed the mark. The 991 has none of the engine design faults that the 930, 964,993,996,997 had - its a huge leap from the 930s thermal reactors that could melt rear tires and fuel lines, the cheap airbox and timing chain connectors of 80s cars, the lack of valve stem guides on early 964s, the rms/ims issues on 996s, the cheap toy like hose connectors on the 997s etc etc etc. The 911 motors before the 996s weighed way more than a Corvette V8 mall block and had more issues than listings in a NYC phone book.  Better than a Alfa Romeo, but there was never any reliability perfection, but the driving experience was perfection.