What do you do when someone reports a bug on a device you don't have, and you can't reproduce it on one of the devices you do have? Genuinely curious (I'm a software developer but not on Android).
Usually its not device specific issues but Manufacturer specific issues. Same issues you encounter on Galaxy S4, you would notice on Galaxy S3, Note etc. Having a handset from each of major manufacturer is good enough for 99% of devs.