PX 12's are a decent binding for beginner to intermediate skiers but after that point, yes there can be problems with durability. I wouldn't bother considering tyrolias, and in my personal opinion I don't think the salomon bindings are that great.
The PX14 is actually a fairly decent upgrade over the PX12. A much beefier heel piece. I have a set on my Bentchetlers and am really really impressed with them. If you want to save some loot then consider those. If money isn't an issue that buy Rossi FKS or Look Pivots (same binding) They are the best. Period no questions asked. Super solid and durable with excellent hold. I got a set for my park skis last year and will never put anything different on my skis from here on out.