The potential pitfall of restoration is the cost versus how good the restoration actually is ie wether its done correctly and at a sensible price. The is a massive industry out there as we know and its not straightforward regaring value for money. The figures can be crazy !! No wonder some restorations are carried out in far away countries now .
You're absolutely right, I've seen more bad restorations than good ones.
And then there's the question - what is a "full restoration" ? In my opinion it means taking the car back to its component parts and returning everything back to "as built" condition (and hopefully better.)
That includes dismantling and rebuilding all mechanical and electrical components, including the gearbox and differential for example.
To do the job to that extent is a costly exercise and for the majority of cars it doesn't make financial sense.
My car still needs completing and a few details correcting but I'm certainly looking forward to seeing it completed, as is my bank manager !
Regarding the Jaguar restored cars, I've also spoken to a marque expert who confirms that they're not as "sharp" as they should be. Unsurprisingly it will take time for them to get the correct levels of knowledge and expertise in place.