What bad reports have you heard? Were they from people who were actually using them or from the arm chair proffessor brigade?
Keep in mind, lithium ion is the group name for all batteries containing lithium, there are a lot of different chemistries in that group and only 1 type at the moment appears to suit mobile house batteries, that's LiFeP04. There is another chemistry just starting to show promise, salt water
batteries, but these are for ground based type house batteries due to their size and weight. If you Google
Aqion you can find out more about these salt water