Rock solid when I have the ELK actuate a light but status is still the main problem. As I understand it, the just released update to ELK RP allows you to read a file from the
ISY-26 which should fix most of the remaining issues with ELK+Insteon but I haven't been able to try this yet. I am anxious to hear if someone gets this working and how it's done. I haven't found any documentation on this other than in the release notes to ELK RP and that only indicates it's possible.
What you heard about PowerHome is true. I don't know about HomeSeer but I do know Indigo does not currently have this ablilty. I suspect link management will come soon to Indigo but wouldn't really help with the ELK at all.
Don't be too discouraged, things are constantly improving and for the most part work very well.
Good Luck.