Having only been into gens until recently (Not Panerai's) I am really impressed by the reps I have seen so far. I have been in and compared my 061 copy to a gen 177 (glass and case) and I have a Nob 177 on order. The only area that jarr's is the glass, hoping the Noob will be better and I will try and fit a gen glass to my 061.
I would now only buy a non rep-able gen, and try and only buy a rep that looks gen enough for 99%. I have tried numerous Gen Pan's on and have no desire to buy one, just improve the glass on my 061 copy and spend my money on other things. I may buy a gen JLC reverso.
I love the Original Rolex Daytona but I'd never buy one, £20k for something that is very repp'd ?!
Some watches are difficult to rep, Patek's, JLC, Brequet, etc. Some are much more easily Repp'd AP, Pan, Rolex etc. The answer for me is there and more importantly the reasons why.