Problems with sensors (NFC, etc), touch screen freezes, see :
https://wiki.merproject.org/wiki/Adaptations/libhybris
https://wiki.merproject.org/wiki/Ada...for_hammerhead
http://talk.maemo.org/showthread.php?t=94620&page=41

I suggest Matias to consider 2 things :
- the majority of users have Jolla smartphone, so to better deal to solve bugs and implement features 100% compatible, it is recommended to have the same plataform (hardware+software). For example, I've only one N900, with Maemo 5 in standard configuration (many softwares installed, overclocking, but no CSSU, new kernels, etc) to maintain compatbility for developing and testing softwares;
- avoid using the new smartphone wth Sailfish OS in normal use, use just at home (for development, etc), to avoid being lost 3rd time. Where it is dangerous, there are cheaper phones available to use. This problem is common in Brazil, where e.g,, a high-end new iPhone costs US$1000 and they are a target for thiefs.