The 5070 vs 5170 or 5970 vc 5270 is not only about the movement but imo more about the asthetics
I do prefer the 5070 BY far, I've seen the 5170 and it is a very nice watch. If I had the money I would buy a 5170 too ... 100% sure. But the 5070 is for me and a lot of others the bette rlooking watch.Between the 5970 and 5270, I like the 5970 and might prefer the 5970 but since I did not see a 5270 yet I'm not 100% sure.
Now, about the movement, you said the inhouse is probably better than the heavily modified Lemania. Well, probably you are correct but that's (imo) not the point. Those movements are so good that being a few % better doesn't make any difference anymore
What makes a difference is the fact that the one is discontinued and was always sought after. In the future Production numbers will grow because of the Asian demand. So if there will be made 5000 5170 and 5000 5270 PP by the year 2025, the inhouse will be not that rare, not compared with the old Lemania.
Look at several other examples, why do you think a Zenith based daytona ( 16520 ) is more expensive than a inhouse 116520 ? In 1999 the 16520 was a lot cheaper than the 116520 today but secondhand a 16520 is more expensive than a newer 116520. Or look at Panerai. A Pre Vendôme with a CHEAP ETA is several times more expensive than a 2003 ETA based or 2010 inhouse movement Panerai. Collectors want the most rare. Or why do you think a Rolex 16610 LV (green bezel) is a more expensive than the regular 16610 sub black bezel. The only difference is a stupid green bezel. BUT Rolex made 5 or 6 times more black subs than green subs between 2004 and 2010. And since they are now discontinued the secondhand price goes up too.
Now, if the 5170 and 5270 would be discontinued in 2013 because Patek would have made ( for some strange reason ) a completely OTHER inhouse movement and put it in a very different case, than ofcourse the 5170/5270 would become very sought after
I don't think most people will prefer a 5070 over a 5170 because they have one but simply because they really love it much more ... or they think about the collectibilty factor
. The 5170 will be made a long time and if you start saving you can always get a 5170.
Now, not many people here have a 2499, more people have a 3970 or 5970. But I'm sure almost everybody will prefer a 2499 and not a 3970/5970. So when you say : "My feeling is that people always prefer what they have bought themselves and given that only a few people have the new pieces but many more (relatively speaking) have the older pieces here, the loyalty to what they already own is driving a unfair evaluation.That's human nature of course" I really can not agree.
This message has been edited by Bruno.M1 on 2011-03-30 10:08:53

Great question to which you have already received some great answers.
I have yet to see the new PP manual movement, but the mere fact that it is manufactured in-house means nothing to me. Given that historically all watch movements were sourced from outside at a time when Patek was building the reputation it now enjoys makes me perfectly comfortable if not delighted to have the Lemania.
There is also the Philippe Stern interview done in 2003 in which Stern stated that it made no sense given production numbers of that era to create its own in-house movement, but that if it did it would "probably been identical to the [Lemania] we currently use." As I read the interview, the justification to incur the cost for building a new movement in-house was based upon the need for increased production and the need for financial and technical independence. It seems evident that he couldn't have Hayek/Breguet or others dictating terms to Patek. So now the new movement will be reproduced for decades to justify the R&D cost, while the Lemania will be confined to a relatively few special watches.
But regardless of the movement, for me it still comes down to the overall aesthetics of the watch. I had the 3970, and while I very much appreciate the watch, it wasn't for me. I did not need to justify my purchase of the 3970. I just sold it and bought the 5970. But I don't feel the slightest urge to sell the 5970 to buy the 5270. On the other hand, if I loved the 5270 over the 5970, I would most likely ignore the fact that it wasn't a Lemania movement and buy it anyway.
Tlw
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