I'll respond here because this is what I found searching on SH3132. I purchased the 214270 for the same reasons. The winding mechanism and wheel train accept Rolex original or after market parts (still not cheap) so can be serviced, the balance assembly, however, looks like Seagull and is a pain to regulate accurately. The recommendation for service is because even though the parts are OK the assembly and oiling may be done haphazardly by less skilled labor, resulting in excessive wear and unexpected performance. I think it's cool the movement could fool a casual observer, but the need to wait weeks for a service by a community watchmaker and seeing the basic balance wheel under a loupe has been sobering reality check.
As to the SA3135 it is an entirely different movement that does not have interchangeable parts and is even more hassle to service. Dealer websites are notoriously error prone: do your research and interact with a TD.