I wish you luck but sharing a bit of my experience its not pretty but I do hope it keeps getting better.
1. Ease of conversion only real issue was pthread_cancel in my case
2. Excellent performance must faster than java in some heavy cpu encryption cases
1. With much research I still cannot get a gl context without java
2. Targeting multiple devices is a pain I must be doing something wrong but that leads to 3. Out of the 4 devices in my home apparently there are 3 different types of arm cores which makes sense being some are old and 1 is a media player but I still havent been able to get all of them to work.
3. Horrible docs alot of things are not documented
4. pthread_cancel is non existent and probably more but thats just something my project was using that it cant anymore.
I hope this is just me and not the ndk itself this has just been my experience and I have never compiled for arm devices before maybe someone knowing more can put tell if the cons are just me or not I would be interested to know.
One note about my findings so far I have not done audio so thats a bit scary as the library we were using is not capable and were looking for low level audio im not sure how well it will come out.