Mr. CL, i am going to be honest, 1436 is a split chrono, 3448 being a perpetual is nowhere close. Because both are vintage pieces, the choice of metal does merit , lets say, 1436J vs 3448P, rarity will get points added into your consideration. Condition is also very important, a mint 3448wg with original boxes and papers, compare to a well polished, hallmarks all gone, no box, no paper 1436J ... that would be something you should consider as well.
The reason why most people lean towards modern pateks, simply because to hunt down a mint condition vintage is just too difficult. To most collectors buying a patek 5004 will probably solve the problem u are asking now. With all the trimmings and probably with change $$.
One other thing you need to consider, repairs and maintenance. IF you choose a 5970, the chances of it breaking down is probably 0%. Should your choice be it 1436, well, you better set aside 18 months, more $$ and probably some frustrations. Auction house "A" sent a split officer case chrono for overhaul, it took 2 years, and not to mention a few hundreds of your well earned buckaroos.
Happy hunting ....